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Title: Forge Work
Author: Ilgen, William L.
Language: English
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Copyright Status: Not copyrighted in the United States. If you live elsewhere check the laws of your country before downloading this ebook. See comments about copyright issues at end of book.

*** Start of this Doctrine Publishing Corporation Digital Book "Forge Work" ***

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Transcriber’s Notes.

The spelling, punctuation and hyphenation from the original has been
retained except for apparent typographical errors.

  Italic text is marked _thus_.
  Bold text is marked =thus=.

  In Chapter ‘FORMULAS AND TABLES’,
  ‘7. WEIGHTS AND AREAS OF SQUARE AND ROUND BARS....’
  [square] represents a square symbol in the original and
  [round] represents a circular symbol.



[Illustration: A MANUAL TRAINING FORGE SHOP]



FORGE WORK

  BY
  WILLIAM L. ILGEN
  FORGING INSTRUCTOR, CRANE TECHNICAL HIGH SCHOOL
  CHICAGO, ILLINOIS

  WITH EDITORIAL REVISION BY
  CHARLES F. MOORE
  HEAD OF MECHANICAL DEPARTMENT, CENTRAL HIGH
  SCHOOL, NEWARK, NEW JERSEY

  NEW YORK  CINCINNATI  CHICAGO
  AMERICAN BOOK COMPANY



  COPYRIGHT, 1912, BY
  WILLIAM L. ILGEN.

FORGE WORK.

W. P. I



PREFACE


Teachers of forge work generally supply their own course of instruction
and arrange the exercises for practice. The necessary explanations and
information are given orally, and hence often with very unsatisfactory
results, as the average student is not able to retain all the essential
points of the course. It was the desire to put this instruction in some
permanent form for the use of forge students that led the author to
undertake this work.

The author wishes to express his thanks for the advice and
encouragement of his fellow-teachers, Dr. H. C. Peterson, Mr. Frank
A. Fucik, and Mr. Richard Hartenberg. Special obligations are due to
Mr. Charles F. Moore, Head of the Mechanical Department in the Central
Commercial and Manual Training High School of Newark, New Jersey, for
his valuable editorial service.

Figures 146, 147, 150, 153, 157, and 158 have been reproduced,
by permission of the publishers, from “Manufacture of Iron” and
“Manufacture of Steel,” copyrighted 1902, by the International Textbook
Company. Acknowledgments are due also to the Inland Steel Company for
the privilege of using Figures 145, 148, 149, 159-163, 166; and to the
Columbia Tool Steel Company for the use of Figures 151, 152, 154-156.

WILLIAM L. ILGEN.



TABLE OF CONTENTS


                                                             PAGE
  CHAPTER I. TOOLS AND APPLIANCES.--1. The Forge; 2.
    Fire Tools; 3. Fuels; 4. The Anvil; 5. The Hammers; 6.
    The ball peen hammer; 7. The cross peen hammer; 8. The
    straight peen hammer; 9. The sledges; 10. The Tongs;
    11. The flat-jawed tongs; 12. The hollow bit tongs;
    13. The pick-up tongs; 14. The side tongs; 15. The
    chisel tongs; 16. The link tongs; 17. The tool or box
    tongs; 18. Anvil and Forging Tools; 19. The hardy; 20.
    The cold and hot cutters; 21. The hot cutter; 22. The
    flatter; 23. The square- and round-edged set hammers;
    24. The punches; 25. The top and bottom swages; 26.
    The top and bottom fullers; 27. The button head set or
    snap; 28. The heading tool; 29. The swage block; 30.
    The surface plate; 31. The tapered mandrels; 32. Bench
    and Measuring Tools; 33. The bench or box vise; 34. The
    chisels; 35. The center punch; 36. The rule; 37. The
    dividers; 38. The calipers; 39. The scriber or scratch
    awl; 40. The square; 41. The bevel; 42. The hack saw;
    43. The files                                               1


  CHAPTER II. FORGING OPERATIONS.--44. The Hammer Blows;
    45. The upright blow; 46. The edge-to-edge blow; 47.
    The overhanging blow; 48. The beveling or angle blows;
    49. The leverage blows; 50. The backing-up blows;
    51. The shearing blow; 52. Forging; 53. Drawing; 54.
    Bending; 55. Upsetting; 56. Forming; 57. Straightening;
    58. Twisting; 59. Welding; 60. The Material for
    Welding; 61. Heating; 62. Scarfing; 63. The lap weld;
    64. The cleft weld; 65. The butt weld; 66. The jump
    weld; 67. The V weld                                       30


  CHAPTER III. PRACTICE EXERCISES.--68. Staple; 69. Draw
    Spike; 70. S Hook; 71. Pipe Hook; 72. Gate Hook; 73.
    Door Hasp; 74. Hexagonal Head Bolt; 75. Square-cornered
    Angle; 76. Fagot Welding; 77. Round Weld; 78. Flat
    Right-angled Weld; 79. T Weld; 80. Chain Making; 81.
    Welded Ring; 82. Chain Swivel; 83. Chain Swivel; 84.
    Chain Grabhook                                             58


  CHAPTER IV. TREATMENT OF TOOL STEEL.--85. Selecting and
    Working Steel; 86. Uses of Different Grades of Steel;
    87. Injuries; 88. Annealing; 89. Hardening and
    Tempering; 90. Casehardening                               83


  CHAPTER V. TOOL MAKING AND STOCK CALCULATION.--91. Tongs;
    92. Heavy Flat Tongs; 93. Light Chain Tongs; 94. Lathe
    Tools; 95. Brass Tool; 96. Cutting-off or Parting Tool;
    97. Heavy Boring Tool; 98. Light Boring or Threading
    Tool; 99. Diamond Point Tool; 100. Right Side Tool;
    101. Forging Tools; 102. Cold Chisel; 103. Hot Cutter;
    104. Cold Cutter; 105. Square-edged Set; 106. Hardy;
    107. Flatter; 108. Small Crowbar; 109. Eye or Ring
    Bolts; 110. Calipers; 111. Stock Calculation for Bending   96


  CHAPTER VI. STEAM HAMMER, TOOLS, AND EXERCISES.--112. A
    Forging; 113. The Drop Hammer; 114. Presses; 115. The
    Steam Hammer; 116. Steam Hammer Tools; 117. The hack
    or cutter; 118. The circular cutter; 119. The trimming
    chisel; 120. The cold cutter; 121. The checking tool or
    side fuller; 122. The fuller; 123. The combined spring
    fullers; 124. The combination fuller and set; 125. The
    combined top and bottom swages; 126. The top and bottom
    swages; 127. The bevel or taper tool; 128. The V block;
    129. The yoke or saddle; 130. Bolsters or collars; 131.
    Punches; 132. Steam Hammer Work; 133. Crank Shaft; 134.
    Connecting Rod; 135. Rod Strap; 136. Eccentric Jaw;
    137. Hand Lever; 138. Connecting Lever; 139. Solid
    Forged Ring; 140. Double and Single Offsets               123


  CHAPTER VII. ART SMITHING AND SCROLL WORK.--141. Art
    Smithing; 142. Scroll Fastenings; 143. Scroll Former;
    144. Bending or Twisting Fork; 145. Bending or Twisting
    Wrench; 146. Clip Former; 147. Clip Holder; 148.
    Clip Tightener or Clincher; 149. Jardinière Stand or
    Taboret; 150. Umbrella Stand; 151. Reading Lamp; 152.
    Andirons and Bar; 153. Fire Set; 154. Fire Set
    Separated                                                 146


  CHAPTER VIII. IRON ORE, PREPARATION AND SMELTING.--155.
    Iron Ore; 156. Magnetite; 157. Red hematite; 158.
    Limonite or brown hematite; 159. Ferrous carbonate;
    160. The Value of Ores; 161. Preparation of Ores;
    162. Weathering; 163. Washing; 164. Crushing; 165.
    Roasting or calcination; 166. Fuels; 167. Fluxes; 168.
    The Blast; 169. The Reduction or Blast Furnace; 170.
    Classification of Pig Iron; 171. Bessemer iron; 172.
    Basic iron; 173. Mill iron; 174. Malleable iron; 175.
    Charcoal iron; 176. Foundry iron; 177. Grading Iron       161


  CHAPTER IX. THE MANUFACTURE OF IRON AND STEEL.--178.
    Refining Pig Iron; 179. The Open-hearth or Finery
    Process; 180. The Puddling Process; 181. Steel; 182.
    The Crucible Process; 183. The Bessemer Process; 184.
    The Open-hearth Process                                   177


  FORMULAS AND TABLES                                         197

  INDEX                                                       207



  DEDICATED
  TO THE MEMORY OF
  MR. DAVID GORRIE

[Illustration: FIG. 1.—THE FORGE.]



FORGE WORK



CHAPTER I

TOOLS AND APPLIANCES


=1. The Forge.=—The forge is an open hearth or fireplace used by
the blacksmith for heating his metals. The kind most commonly used by
the general smiths is such as can be seen in small villages or where
the ordinary class of blacksmithing is done. (See Fig. 1.)

Forges are usually built of brick; in form they are square or
rectangular, and generally extend out from a side wall of the shop. The
chimney is built up from the middle of the left side and is provided
with a hood _B_, which projects over the fire sufficiently to catch the
smoke and convey it to the flue.

The fire is kindled on the hearth _A_ under the hood and over the
tuyère iron. This iron, the terminal of the blast pipe that leads from
the bellows _E_, is made in various forms and of cast iron; sometimes
it has a large opening at the bottom, but often it has none.

The bellows are operated by the lever _F_, which expands the sides and
forces air through the tuyère iron, thereby causing the fire to burn
freely and creating a temperature sufficient for heating the metals.

The coal box _C_ is to the right, where it is convenient. The coal
should always be dampened with water to prevent the fire from
spreading. This will produce a more intense and more concentrated heat,
so that a certain part of the metal can be heated without danger of
affecting the rest.

[Illustration: FIG. 2.—A MANUAL TRAINING FORGE.]

The water tub, or slack tub _D_, as it is more properly called, stands
at the right of the forge near the coal box, where the water for
dampening the coal can be most readily obtained. It is used for cooling
the iron or tongs and for tempering tools.

Modern forges are made of cast iron or sheet steel. There are various
kinds designed mostly for special purposes. They are generally used
with the fan blast instead of the bellows and have a suction fan for
withdrawing the smoke.

The forge illustrated in Fig. 2 was designed for manual training use
and is excellent for such a purpose. The bottom or base has six drawers
which provide convenient places for keeping exercises and individual
tools. As each drawer is provided with a special lock, much of the
trouble resulting from having the tools or the work mislaid or lost is
prevented.

[Illustration: FIG. 3.—SECTIONAL VIEW OF THE FORGE SHOWN IN FIG.
2.]

The hearth _A_ where the fire is built is provided with a cast-iron
fire pot or tuyère. This is constructed with an opening at the bottom
where there is a triangular tumbler which is cast upon a rod projecting
through the front of the forge; by revolving the rod and tumbler the
cinders or ashes can be dropped into the ash drawer at the bottom of
the forge without disturbing the fire. A sectional view of these parts
is shown in Fig. 3, also the valve which regulates the blast.

Suspended on the upper edge surrounding the hearth, and located to the
right and left of the operator, two boxes _C_ and _D_ are located,
which are used for storing an adequate supply of coal and water, where
they may be conveniently obtained.

In front are two handles; the upper one operates the clinker or ash
valve, the lower one regulates the blast.

The front and back edges surrounding the hearth are cut out, so that
long pieces of metal can be laid down in the fire. These openings can
be closed, when desired, with the hinged slides shown at _G_.

The hood _B_ projects over the fire sufficiently to catch the smoke and
convey it to the opening of the down-draft pipe _E_. When necessary
the hood can be raised out of the way with the lever _F_, which is
constructed with cogs and provided with a locking pin to keep the hood
in position.


=2. Fire Tools.=—The necessary tools required for maintaining the fire
and keeping it in good working condition are shown in Fig. 4. _A_ is
the poker with which the coke can be broken loose from the sides. _B_
is the rake with which the coke can be moved over the fire on top of
the metal to prevent the air from retarding the heating. The shovel _C_
is used for adding fresh coal, which should always be placed around the
fire and not on top. In this way unnecessary smoke will be prevented,
and the coal will slowly form into coke. The dipper _D_ is used for
cooling parts of the work that cannot be cooled in the water box. The
sprinkler _E_ is used for applying water to the coal, or around the
fire to prevent its spreading.

[Illustration: FIG. 4.—FIRE TOOLS.

_A_, poker; _B_, rake; _C_, shovel; _D_, dipper; _E_, sprinkler.]


=3. Fuels.=—The fuels used for blacksmithing are coal, coke, and
charcoal. Most commonly a bituminous coal of superior quality is used.
It should be free from sulphur and phosphorus, because the metals will
absorb a certain amount of these impurities if they are in the fuel.
The best grade of bituminous coal has a very glossy appearance when
broken.

Coke is used mostly in furnaces or when heavy pieces of metal are to be
heated. It is a solid fuel made by subjecting bituminous coal to heat
in an oven until the gases are all driven out.

Charcoal is the best fuel, because it is almost free from impurities.
The most satisfactory charcoal for forging purposes is made from
maple or other hard woods. It is a very desirable fuel for heating
carbon steel, because it has a tendency to impart carbon instead of
withdrawing it as the other fuels do to a small extent. It is the most
expensive fuel, and on that account, and because the heating progresses
much more slowly, it is not used so generally as it should be for
heating carbon steel.


=4. The Anvil.=—The anvil (Fig. 5) is indispensable to the smith, for
upon it the various shapes and forms of metal can be forged or bent
by the skilled workman. Except for a few that have been designed for
special purposes, it has a peculiar shape which has remained unchanged
for hundreds of years. That the ancient smiths should have designed one
to meet all requirements is interesting to note, especially as most
other tools have undergone extensive improvements.

Anvils are made of wrought iron or a special quality of cast iron. In
the latter case the face is sometimes chilled to harden it, or is made
of steel which is secured to the base when the anvil is cast. Those
that are made of wrought iron are composed of three pieces: the first
is the base _B_ which is forged to the required dimensions; the second
is the top which includes the horn _C_ and the heel; the third is the
face _A_ of tool steel which is welded to the top at the place shown by
the upper broken line. The top and base are then welded together at the
lower broken line.

[Illustration: FIG. 5.—THE ANVIL.]

After the anvil has been finished, the face is hardened with a constant
flow of water, then it is ground true and smooth and perfectly straight
lengthwise, but slightly convex crosswise, and both edges for about
four inches toward the horn are ground to a quarter round, thus
providing a convenient place for bending right angles. This round edge
prevents galling, which is liable to occur in material bent over a
perfectly square corner.

The round hole in the face is called the pritchel hole, over which
small holes can be punched in the material. When larger ones are to be
punched, they can be made on a nut or collar placed over the square
hole or hardy hole. This hardy hole is used mostly for holding all
bottom tools, which are made with a square shank fitted loosely to
prevent their becoming lodged.

The flat portion _D_ at the base of the horn, and a little below the
level of the face, is not steel, consequently not hardened, and is
therefore a suitable place for cutting or splitting, because there
is not much liability of injuring the cutter if the latter comes in
contact with the anvil.

The horn _C_ is drawn to a point and provides a suitable place for
bending and forming, also for welding rings, links, or bands.

The anvil is usually mounted on a wooden block and is securely held by
bands of iron as shown in the illustration, or it may be fastened by
iron pins driven around the concave sides of the base. It is sometimes
mounted on a cast-iron base made with a projecting flange which holds
the anvil in place.

A convenient height for the mounting is with the top of the face just
high enough to touch the finger joints of the clenched hand when one
stands erect. It is generally tipped forward slightly, but the angle
depends considerably upon the opinion of the workman who arranges it in
position.

For some time most of the anvils were made in Europe, but at present
the majority that are purchased here are made by American manufacturers.


=5. The Hammers.=—Of the multitude of tools used by mechanics, the
hammer is undoubtedly the most important one. There was a time when man
had only his hands to work with, and from them he must have received
his ideas for tools. Three prominent ones which are used extensively
at present were most probably imitations of the human hand. From the
act of grasping, man could easily have originated the vise or tongs for
holding materials that he could not hold with the hand. Scratching with
the finger nails undoubtedly impressed him with the need of something
that would be effective on hard substances, and so he devised such
tools as picks, chisels, and numerous other cutting instruments.

The clenched fist must have suggested the need of a hammer. The first
thing to be substituted for the fist was a stone held in the hand. Next
a thong of fiber or leather was wound around the stone, and used as a
handle. From these beginnings we have progressed until we have hammers
of all sizes and shapes, from the tiny hammer of the jeweler to the
ponderous sledge. Workmen have adapted various shapes of hammers to
their individual needs.

[Illustration: FIG. 6.—HAND HAMMERS.

_A_, ball peen hammer; _B_, cross peen hammer; _C_, straight peen
hammer.]


=6. The ball peen hammer= (_A_, Fig. 6), sometimes called a machinist’s
hammer, is very conveniently shaped for forging, as the ball end is
handy for drawing out points of scarfs or smoothing concave surfaces.
A suitable weight of this kind of hammer is one and a half pounds, but
lighter ones can be used to good advantage for fastening small rivets.


=7. The cross peen hammer= (_B_, Fig. 6) is one of the older styles and
is mostly employed in rough, heavy work or for spreading metal.


=8. The straight peen hammer= (_C_, Fig. 6) is shaped similarly to the
ball peen hammer, except that the peen is flattened straight with the
eye. It is convenient for drawing metal lengthwise rapidly.

=9. The sledges= (_A_, _B_, and _C_, Fig. 7) are used for striking on
cutters, swages, fullers, or other top tools; when they are used by the
helper, the blacksmith can be assisted in rapidly drawing out metal.
The only difference between these two sledges is in the peen--one is
crosswise with the eye and the other lengthwise. The double-faced
sledge _C_ is sometimes called a swing sledge, because it is used
mostly for a full swing blow.

[Illustration: FIG. 7.—THE SLEDGES.]


=10. The Tongs.=—There is an old saying that “a good mechanic can do
good work with poor tools,” which may be true; but every mechanic
surely should have good tools, on which he can rely and thereby have
more confidence in himself. Among the good tools that are essential for
acceptable smith work are the tongs.

Very few shops have a sufficient variety of tongs to meet all
requirements, and it is often necessary to fit a pair to the work to be
handled. Sometimes quite serious accidents happen because the tongs are
not properly fitted. They should always hold the iron securely and, if
necessary, a link should be slipped over the handles as shown in _B_,
Fig. 8. The workman is thus relieved from gripping the tongs tightly
and is allowed considerable freedom in handling his work.


=11. The flat-jawed tongs= are shown at _A_, Fig. 8. They are made in
various sizes to hold different thicknesses of material. Tongs of this
kind hold the work more securely if there is a groove lengthwise on the
inside of the jaw; the full length of the jaw always should grip the
iron.

[Illustration: FIG. 8.—THE TONGS.

_A_, flat-jawed tongs; _B_, hollow bit tongs; _C_, pick-up tongs;
_D_, side tongs; _E_, chisel tongs; _F_, link tongs; _G_, tool or box
tongs.]


=12. The hollow bit tongs=, shown at _B_, Fig. 8, are very handy for
holding round iron or octagonal steel. They can be used also for
holding square material, in which case the depressions in the jaws
should be V-shaped.


=13. The pick-up tongs= (_C_, Fig. 8) are useful for picking up large
or small pieces, as the points of the jaws are fitted closely together,
and the two circular openings back of the point will securely grip
larger pieces when seized from the side.


=14. The side tongs= (_D_, Fig. 8) are used for holding flat iron from
the side. Tongs for holding round iron from the side can be made in
this form with circular jaws.


=15. The chisel tongs= are shown at _E_, Fig. 8. One or more pairs of
these are necessary in all forge shops. As the hot and cold cutters
frequently get dull or broken, it will be necessary to draw them out
and retemper them; and, as the heads of these cutters become battered
considerably, they are difficult to hold without chisel tongs. The
two projecting lugs at the ends of the jaws fit into the eye, and the
circular bows back of them surround the battered head of the cutter, so
that it can be held without any difficulty.


=16. The link tongs= (_F_, Fig. 8) are as essential as anything else
required in making chains or rings of round material. They can be made
to fit any size of stock.


=17. The tool or box tongs= (_G_, Fig. 8) should be made to fit the
various sizes of lathe tool stock that are used. They should be made
substantially and fit the steel perfectly so that it can be held
securely and without danger of stinging the hand, while the tool
is being forged. Another style of tool tongs is made with one jaw
perfectly flat; on the other jaw, lugs are provided to hold the steel
firmly. These are not illustrated.

Almost an unlimited number of different tongs could be explained and
illustrated, but, from those given, any one should be able to add to or
change the tongs he has so that his material can be securely held.


=18. Anvil and Forging Tools.=—If a complete set of these tools were to
be illustrated and explained, a volume would be required. Even then,
the worker would very often be compelled to devise some new tool to
suit the particular work at hand. One advantage that the blacksmith has
over all other mechanics is that when a special tool is required, if he
is a thorough mechanic he can make it.

An almost unlimited number of tools might be required in a general
smith shop; but only such tools as are essential in manual training or
elementary smith work will be considered here.

[Illustration: FIG. 9.

_A_, hardy; _B_, cold cutter; _C_, hot cutter.]


=19. The hardy= (_A_, Fig. 9) should fit the hardy hole of the anvil
loosely enough so that it will not stick or wedge fast. It is made of
cast steel and should be tempered so that it will not chip or batter
from severe use. It is an indispensable tool, especially to one who
has to work without a helper, for with it iron can be cut either hot
or cold, and steel when it is heated. The material should be held on
the cutting edge of the hardy, then struck with the hammer. A deep cut
should be made entirely around the material, round, square, or flat,
so that it can be broken off by being held over the outer edge of the
anvil and struck a few downward blows with the hammer.

Material should not be cut through from one side, for the cut would
then be angular instead of square; furthermore, there would be the
effect of dulling the hardy if the hammer should come in contact with
it. The hardy is frequently used to mark iron where it is to be bent or
forged, but it is not advisable to use it for such purposes, unless the
subsequent operations would entirely remove the marks, for they might
be made deep enough to weaken the metal, especially at a bending point.


=20. The cold and hot cutters= (_B_ and _C_, Fig. 9) are made, as are
all other top tools, with an eye for inserting a handle, and should
be held by the workman while some one acting as his helper strikes
on them with the sledge. The handles can be of any convenient length
from eighteen inches to two feet. Cast steel should be used for making
both these cutters, but their shapes differ somewhat. The cold cutter
_B_ is forged considerably heavier on the cutting end than is the hot
cutter, in order to give it plenty of backing to withstand the heavy
blows that it receives. The cutting edge is ground convex to prevent
the possibility of the corners breaking off easily, and is ground more
blunt than the hot cutter. It should be used only to nick the metal,
which should then be broken off with the hammer or sledge, as described
in cutting iron with the hardy.


=21. The hot cutter= (_C_, Fig. 9) is drawn down, tapering from two
depressions or shoulders near the eye to an edge about 1/8 inch thick,
which is ground equally from both sides to form a cutting edge parallel
with the eye. It should be used exclusively for cutting hot metal,
because the shape and temper will not stand the cutting of cold iron.
In order to avoid dulling the cutter and the possibility of injuring
some one with the piece of hot metal that is being cut off, the cut
should be held over the outside edge of the anvil when the final blows
are being struck; the operation will then have a shearing action, and
the piece of metal will drop downward instead of flying upward.

Great care should be taken in hardening and tempering each of these
cutters to prevent possible injury from small particles of steel that
might fly from them if they were tempered too hard. The cold cutter
should be hard enough to cut steel or iron without being broken or
battered on its cutting edge. The hot cutter should not be quite so
hard and should be dipped in water frequently when it is being used to
prevent the temper from being drawn.


=22. The flatter= (_A_, Fig. 10) is as useful and as essential for the
production of smooth and nicely finished work as the finishing coat of
varnish on a beautiful piece of furniture. Any work that is worth doing
is certainly worth doing well, and in order to make forge work present
a finished appearance the smith should use the flatter freely. With
it the rough markings of the various forging tools or hammer can be
entirely removed. By using it while the work is at a dull red heat, and
by occasionally dipping the flatter in water before it is applied, all
the rough scale can be removed, thus leaving the work with a smooth,
finished appearance.

There are various sizes of this tool, but one with a 2-inch face is
convenient for use on light forgings. The edges of the face may be made
slightly round, so that markings will not be left on the work, but
frequently the edges are left perfectly square.

[Illustration: FIG. 10.

_A_, flatter; _B_, square-edged set hammer; _C_, round-edged set
hammer.]

It is not necessary to temper this tool; in fact, the constant
hammering on it has a tendency to crystallize the steel, often causing
it to break off at the eye. As the constant hammering on the head of
the flatter will also cause the head to become battered, it is good
practice frequently to draw out the head and lay the flatter aside to
cool. This will anneal the steel and prevent crystallization, at least
for some time.


=23. The square-and round-edged set hammers= (_B_ and _C_, Fig. 10)
are employed for various purposes. The former is used for making
square shoulders or depressions such as could not be produced with
the hand hammer alone, or for drawing metal between two shoulders
or projections. The latter is used for the same purposes, with the
exception that it produces a rounded fillet instead of a square corner.
It is also convenient for use in small places where the flatter cannot
be employed.

The sizes of these tools vary according to the requirements of the
work, but it is advisable to have about three sizes of the square-edged
one. A good outfit of set hammers consists of one 5/8-inch, one
3/4-inch, one 1-inch, all square-edged; and one round-edged set with a
1-1/4-inch face. These four should fulfill all requirements for light
forgings. These tools need not be tempered, for the reason explained in
connection with the flatter.


=24. The punches= (_A_, _B_, and _C_, Fig. 11) are merely samples
of the multitude of such tools that may be required. They may be of
various sizes, depending upon the requirements of the work, and either
round, square, or oval in shape at the end. The hand punch _A_ is
held with one hand while blows are delivered with the other. It is
convenient for punching holes in light pieces; but when the work is
heavy the intense heat from the metal makes it impossible to hold a
punch of this kind.

[Illustration: FIG. 11.—THE PUNCHES.]

In such cases the handle punches _B_ and _C_ are employed. They
eliminate the danger of burning the hand, but it is necessary to
have some one act as helper and do the striking. The proper way to
use a punch on hot metal is to drive it partly through, or until an
impression can be seen on the opposite side after the punch has been
removed; then the punch is placed on the impression and driven through
the metal while it is held over the pritchel hole, the hardy hole, or
anything that will allow the punch to project through without causing
the end to be battered. If heavy pieces of metal are to be punched, it
is a great advantage to withdraw the tool, drop a small piece of coal
into the hole, and cool the punch before again inserting it. The coal
prevents the tool from sticking fast, and the operation can be repeated
as often as necessary.

Punches need not be tempered, because the strength of the steel from
which they should be made will withstand the force of the blows, and
also because the metal is generally hot when the punches are used;
therefore the temper would be quickly drawn out of them. If sheet metal
or light material is to be punched cold, it is advisable to harden the
punch slightly; then the hole may be punched through from one side,
while the metal is held on something containing a hole slightly larger
than the punch. This method has the effect of producing a smoothly cut
hole, provided the metal is properly placed.

[Illustration: FIG. 12.—THE TOP AND BOTTOM SWAGES.]


=25. The top and bottom swages= (Fig. 12) are made with semicircular
grooves of different sizes to fit the various diameters of round
material. The former has an eye for the insertion of a handle by which
it is held when in use. The eye should be crosswise to the groove in
the face. The bottom swage is made with a square projecting shank to
fit loosely into the hardy hole of the anvil. It should be placed
in position for use with the groove crosswise to the length of the
anvil, unless the form of the forging should require otherwise. Swages
are conveniently used for smoothing round material after it has been
welded, or for swaging parts of a forging after they have been roughly
hammered out. By dipping the top swage in water occasionally while in
use, the work can be made much smoother and the scale of oxide removed;
this is called water swaging.

[Illustration: FIG. 13.—THE TOP AND BOTTOM FULLERS.]


=26. The top and bottom fullers= (Fig. 13) are made in pairs with
convex semicircular projections or working faces, whose diameters
should correspond, if intended to be used together. As the former is
quite frequently used alone, it may be made of any desired size. The
top fuller, like the top swage, is made to be used with a handle; the
bottom fuller, fitted to the anvil like a bottom swage, generally is
placed for use with the length of its face parallel to the length of
the anvil.

They are used together for forming depressions or shoulders on opposite
sides of the material; from the shoulders thus formed, the metal may
be forged without disturbing them. They are used also for rapidly
drawing out metal between shoulders or projections which may have been
previously made and are to be left undisturbed. The top fuller is used
singly in making scarfs for welding, in forming grooves, in smoothing
fillets and semicircular depressions, or in forming shoulders on only
one side of metal.


=27. The button head set or snap= (_A_, Fig. 14) as it is sometimes
called, has a hemispherical depression on its face. It is used for
making heads of rivets or finishing the heads of bolts. Only a few
different sizes are required, unless considerable riveting or bolt
making is to be done.

[Illustration: FIG. 14.

_A_, the button head set; _B_, the heading tool.]


=28. The heading tool= (_B_, Fig. 14) is used exclusively for forming
the heads of bolts or rivets. Formerly a very large assortment of these
tools was required in a general shop; but as bolts can now be made so
cheaply by modern machinery, there are not many made by hand. It would
be advisable to have a few general sizes, however, because they are
sometimes convenient in making other forgings, and bolt making affords
an instructive exercise.


=29. The swage block= (_A_, Fig. 15) rests on a cast-iron base _B_.
It is a very useful tool in any smith shop and does away with the
necessity of having a large assortment of bottom swages, as only top
swages will be required for large-sized material. The block is made of
cast iron and of different thicknesses. The depressions on the edges
include a graduated series of semicircular grooves that can be used in
place of bottom swages; a large segment of a circle, which is handy
in bending hoops or bands; graduated grooves for forming hexagonal
boltheads or nuts; and sometimes a V-shaped and a right-angled space
used for forming forgings.

[Illustration: FIG. 15.—THE SWAGE BLOCK.]

The holes through the blocks are round, square, or oblong. The round
ones can be used in place of heading tools for large sized bolts, or
in breaking off octagon or round steel after it has been nicked with
the cold cutter. The square holes may be used either for making and
shaping the face of a flatter or a round-edged set hammer, or in place
of a heading tool, when a square shoulder is required under the head.
They may be used, also, for breaking square steel. The oblong holes are
convenient for breaking lathe tool material. Some swage blocks have in
addition a hemispherical depression on the side, convenient for forming
dippers or melting ladles.

The base upon which the swage block rests is constructed with lugs on
the inner side, as indicated by the broken lines on the sketch. Upon
these it is supported, either flat or on any of its four edges. These
lugs prevent the swage block from tipping sidewise.


=30. The surface plate= (_C_, Fig. 16) is generally made of cast iron
about 1-1/2 to 2 inches thick, from 20 to 24 inches wide, and from 3
to 4 feet long. It should be planed perfectly smooth and straight on
its face, the edges slightly round. It should be supported on a strong
wooden bench _D_ and placed somewhere in the middle of the shop so
that it is accessible to all the workmen. On it work is tested to see
whether it is straight, perpendicular, or if projections are parallel.
The anvil is sometimes used for this purpose, but as it is subjected
to such severe use, the face becomes untrue and therefore cannot be
depended upon. A true surface plate is always reliable and convenient
for testing work.

[Illustration: FIG. 16.—THE SURFACE PLATE.]


=31. The tapered mandrels= (Fig. 17) are made of cast iron, and are
used for truing rings, hoops, bands, or anything that is supposed to
have a perfectly circular form. The height ranges from 2-1/2 to 5 feet;
the largest diameter varies from 8 to 18 inches. They are cone-shaped
with a smooth surface, and should be used with caution. The blows
should be delivered on the metal where it does not come in contact with
the mandrel; when bands of flat material are to be trued, the best
method is to place them on the mandrel from each side alternately.
Unless this precaution is observed, the band will be found tapered the
same as the mandrel. Alternating is not so necessary when bands or
rings of round material are handled.

Mandrels are sometimes made in two sections, as shown at _B_ and
_C_. As _B_ is made to fit into the top of _C_, the two parts become
continuous; the smaller one can also be held in the vise or swage
block and thus used separately. They are frequently made with a groove
running lengthwise, which allows work to be held with tongs and
provides a recess for any eyebolt or chain that may be attached to the
ring.

[Illustration: FIG. 17.—THE TAPERED MANDRELS.]

It should not be supposed that all mandrels are of this particular
form; any shape of bar, block, or rod of iron that is used for the
purpose of forming or welding a special shape is called a mandrel.


=32. Bench and Measuring Tools.=—Another set of blacksmith appliances
includes the bench vise, chisels, center punch, rule, dividers,
calipers, scriber, square, bevel, hack saw, and files.

[Illustration: FIG. 18.—THE BENCH VISE.]


=33. The bench or box vise= (Fig. 18) is not ordinarily used in general
blacksmithing. The back jaw of a general smith’s vise extends to the
floor, forming a leg, and is held in position on the floor by a
gudgeon on its end. This vise is not illustrated, because the bench or
box vise is preferable for manual training work.

The vise should be set so that the tops of the jaws are at the height
of the elbows,—a position convenient in filing. It is used for holding
the work for filing, chipping, twisting, and sometimes for bending. But
when it is used for bending, especially when bending a right angle, the
operation should be performed cautiously, for the sharp edges of the
jaws are very liable to cut the inner corner of the angle and cause a
gall which will weaken the metal at the bend.


=34. The chisels= (_A_ and _B_, Fig. 19) are very familiar, yet, though
they are so common, they are the most abused tools used by both skilled
and unskilled workmen. The mere name “cold chisel” seems to convey the
impression to most people that with it they ought to be able to cut
anything. But that impression is wrong; chisels ought to be made of
a certain grade of steel and drawn for either rough or smooth work,
as may be required. Then they should be properly tempered to cut the
material for which they are intended.

A chisel for rough, heavy work should not be drawn too thin or too
broad at the cutting edge. If it is flattened out into a fan-shaped
cutting edge, there should be no surprise if it breaks, for, in order
to make a chisel stand rough usage, it should have sufficient metal to
back up the corners. On the other hand, a chisel for smooth finishing
work can safely be drawn thin but not fan-shaped, as the cuts that
ought to be required of such a chisel should not be heavy. _A_ chisel
for ordinary work ought to be ground so that the two faces form an
angle of 60 degrees; if the work is heavy, it should be ground even
more blunt.

[Illustration: FIG. 19.

_A_, cold chisel; _B_, cape chisel; _C_, center punch; _D_, rule.]

The chisel illustrated at _A_ represents a common cold chisel, which
can be used for various purposes. The chisel _B_ is called a cape
chisel and is used for cutting and trimming narrow grooves and slots.
It is indispensable for cutting key seats in shafting or work of
that kind. On account of its being used in such narrow places it is
necessary to make the cutting edge somewhat fan-shaped to prevent the
chisel from sticking fast; but for additional strength the metal is
allowed to spread, as shown. When using the cape chisel, it is a good
practice occasionally to dip the cutting edge in some oily waste, which
will tend to prevent its wearing away or sticking.


=35. The center punch= (_C_, Fig. 19) should be made of the same
quality of material as the cold chisel. It can be made of steel from
1/4 to 5/8 of an inch in diameter; octagon steel is preferable. After
it has been roughly drawn out, it is ground to a smooth round point,
then it is tempered as hard as it will stand without breaking. It is
used for marking centers of holes to be drilled, or for marking metal
where it is to be bent, twisted, or forged. When used for marking hot
metal, it is frequently made with an eyehole in the body, so that a
small handle can be inserted; this will prevent burning the hands.


=36. The rule= (_D_, Fig. 19) should be of good quality. The one best
adapted for forge work is the 2-foot rule, which is jointed in the
center. It is 3/4 inch wide and is made of either tempered spring steel
or hard rolled brass.

[Illustration: FIG. 20.

_A_, dividers; _B_, calipers; _C_, scriber; _D_, square; _E_, bevel.]


=37. The dividers= (_A_, Fig. 20) are used for measuring distances and
for describing circles. The points are clamped in a rigid position with
the small thumbscrew, which comes in contact with the segmental arc.
Close adjustments can be made with the milled-edge nut on the end of
the segmental arc. When metal is to be bent to a circular form, a good
method is to rub chalk on the surface plate and describe the desired
curve on this chalk. As the markings thus made are not easily removed,
this plan is much better than drawing upon a board.


=38. The calipers= (_B_, Fig. 20) are used for measuring diameters,
widths, and thicknesses. Those illustrated are the kind generally
used in forge work. They are called double calipers and are the most
convenient because two dimensions can be determined by them. As the
accuracy of the work depends on them, they should be well made. In the
illustration here given, each bow is held securely by an individual
rivet. Sometimes they are secured with one; if so, the rivet should be
square in the straight central part and tightly fitted. The projecting
ends of the rivet should be filed round, and the holes in the bowed
sides should be made to fit the round ends of the rivet; then the sides
should be riveted on tight so that each bow may be moved independently
of the other.


=39. The scriber or scratch awl= (_C_, Fig. 20) is used in marking
holes, sawing, chipping, or in laying out distances, which can
afterward be marked with a center punch if required. It should
be made of a good quality of steel, and the point should be well
hardened so that it will cut through the surface scale of the metal. A
suitable-sized steel for making a scriber is 3/16 inch round and the
length over all about 6 inches.


=40. The square= (_D_, Fig. 20) is another indispensable tool when
accurate work is to be produced. Convenient sizes for manual training
work are the 8 × 12-inch, with a 16 × 24-inch for general use.


=41. The bevel= (_E_, Fig. 20) should be used when bending and laying
out angles of various degrees. When metal is to be bent to a given
angle, the pupil should set and use the bevel.


=42. The hack saw= (Fig. 21) is at present considered a necessary part
of any forge shop equipment. It is used for sawing iron or untempered
steel, and when a power shear is not included in the equipment,
considerable filing can be saved by sawing. The frame illustrated is
adjustable so that the blades can be made of different lengths and be
set at right angles to the frame, which is sometimes convenient.

When using the hack saw, make slow, full-swing strokes; when drawing
back for another stroke, it will prolong the efficiency of the blades
if the saw is raised up to prevent the teeth from bearing on the
metal, as the backward stroke is more destructive to the teeth than
the forward or cutting stroke. The blades are made from 8 to 12 inches
in length, 1/2 inch in width, and with from 14 to 25 teeth to the
inch. They are tempered so hard that they cannot be filed, but are so
inexpensive that when they cease to be efficient they may be thrown
away.

[Illustration: FIG. 21.—THE HACK SAW AND FILES.]


=43. The files= (Fig. 21) are illustrated merely to show that they are
to be used for special purposes. As finishing or filing is almost a
trade in itself, the file should not be used in blacksmithing, unless
it is especially necessary. A piece of smith’s work that has been
roughly forged is much more admirable than a highly polished piece that
has been filed into elegance.

Files are round, flat, square, half round, and of numerous other
shapes, and vary in lengths and cuts for rough or smooth filing. Any of
them may be used as required, but it should be remembered that filing
is not blacksmithing.


QUESTIONS FOR REVIEW

  What is the main difference between the old type of smithing forge
  and a modern one? How is the air supplied for each? What is a tuyère
  iron? Describe the hearth. What kind of coal is used for forging?
  Is coal the best fuel for heating all metals? Why is charcoal the
  best fuel for heating carbon steel? How should the fire be built to
  prevent making excess smoke? What other fuel is used in forging?
  What kind of work is it used for? Describe the different parts of
  the anvil. How is a cast-iron anvil hardened? How is a wrought-iron
  anvil hardened? Name and describe the different kinds of hammers.
  Why should the tongs fit properly the iron to be handled? Name and
  describe the different tongs you have been made familiar with. How
  would you secure the tongs to relieve the hand?

  What is a hardy? What is it used for? Explain the proper method of
  using it. Is it always good practice to use a hardy for marking the
  iron? Why? What is the difference between a cold and a hot cutter?
  What is the general use for a flatter? Should it be tempered?
  Why? What are set hammers? What is a punch used for? Explain the
  difference between a hand punch and a handle punch. When punching a
  heavy piece of metal, how is the tool prevented from sticking fast?
  Are all punches tempered? Why? Describe and explain the use of top
  and bottom swages. How should the bottom swage be placed for use?
  What is meant by water swaging? State the effect it has on the iron.
  What are top and bottom fullers used for? Are they always used in
  pairs? How is the bottom one placed for use? What are the button
  head set and heading tool used for? What is the special advantage
  of having a swage block? Explain some of the different uses of that
  tool. What is the special use of the surface plate? What is the
  tapered mandrel used for? Are all mandrels of this particular kind?
  Explain others. Is it good practice to use the vise for bending? Why?
  Describe the cold chisel. Should all cold chisels be made alike? What
  is the center punch used for? Describe the other bench and measuring
  tools mentioned. What is the special objection to using the files?



CHAPTER II

FORGING OPERATIONS


=44. The Hammer Blows.=—Metal can be forced into desired shapes or
forms by delivering the hammer blows in different ways. All hammer
blows are not alike; some will have one effect and others will produce
an entirely different result.


=45. The upright blow= is delivered so that the hammer strikes the
metal in an upright position and fully on the anvil. Such blows
force the metal equally in all directions, providing the surrounding
dimensions are equal. They will also reduce the thickness of the metal
in the direction in which they are delivered, the reduction depending
upon the amount of force put into the blows. They are used for drawing
where the metal is supposed to spread equally in all directions and for
making smooth surfaces.

[Illustration: FIG. 22.—THE UPRIGHT BLOW.]

Figure 22 shows an upright blow as delivered on a piece of flat
material. If the material is as wide as the face of the hammer, or
wider, the force of the blow will spread the metal equally, but if it
is narrower, the blow will lengthen the material more rapidly, because
the hammer will cover more in length than in width.


=46. The edge-to-edge blow= is delivered so that the edge or side of
the hammer face will be directly above the edge or side of the anvil.
When blows are delivered in this manner (_a_, Fig. 23), the hammer
forms a depression on the upper side of the metal and the anvil forms
one on the bottom.

[Illustration: FIG. 23.—THE EDGE-TO-EDGE BLOW.]

When a piece of metal is to be drawn to a smaller dimension, with
shoulders opposite each other, on either two or four sides, these blows
will produce the required result to the best advantage. They are more
effective if the metal is held at a slight angle across the edge of the
anvil face, but then the hammer blows must be delivered a little beyond
the anvil edge, so that the upper and lower depressions in the metal
will be formed exactly opposite each other, as shown at _b_, where the
depressions are indicated by the broken lines.

In forming shoulders such as are required on the hasp exercise (page
64) the first pair may be formed as shown at _b_ and the second pair
as shown at _c_. In the latter case the metal is held across the nearer
edge of the anvil face and the blows delivered in a manner similar to
that described in the preceding paragraph. Hammer blows of this class
may be used on any edge of the anvil as required.


=47. The overhanging blow= is delivered so that half the width of the
hammer face extends over the edge of the anvil. (See Fig. 24.)

[Illustration: FIG. 24.—THE OVERHANGING BLOW.]

It is used for forming shoulders on one side of the metal and for
drawling out points of scarfs. When blows are delivered in this manner,
the anvil will form a depression or shoulder on the lower side of the
metal, and the hammer will keep the metal straight on the upper side.

This blow also will be more effective if the metal is held at a slight
angle across the edge of the anvil face, but the blows must always be
delivered squarely on the upper side of the metal to keep it straight.


=48. The beveling or angle blows= are delivered at any angle that the
form of the work may require. When the metal is to be drawn with a
taper on one side, it must be held level on the anvil and the blows
delivered at an angle determined by the amount of taper required.
Figure 25 shows the manner of holding the metal and the way the blows
are to be delivered.

[Illustration: FIG. 25.—THE BEVELING OR ANGLE BLOW.]

When the metal is to be drawn tapering on two opposite sides, it should
be held to the proper angle on the anvil to establish the taper desired
on the bottom, while the hammer blows are delivered so as to form a
similar taper on the upper side. (See Fig. 25.)

[Illustration: FIG. 26.—DRAWING METAL TO A POINT BY BEVELING OR ANGLE
BLOWS.

_A_, correct position; _B_, incorrect position.]

[Illustration: FIG. 27.—THE LEVERAGE BLOW.]

Blows of this kind are used for chamfering corners or edges, and may be
delivered at any required angle. They are also used when drawing metal
to a point, either square, round, hexagonal, or octagonal, but the
metal should be held on the anvil, as shown at _A_, Fig. 26. Then the
hammer will not come in contact with the face of the anvil, as shown at
_B_. If the hammer strikes the anvil, small chips of steel are liable
to break off from the hammer at the place indicated by _c_, and cause
serious injury.

[Illustration: FIG. 28.—BENDING BY LEVERAGE BLOWS.]


=49. The leverage blows= are used mostly for bending, as they will not
leave marks where the bending occurs. For instance, when a ring is to
be formed, the metal is first held in the tongs and rested on the horn
of the anvil, as shown in Fig. 27. Note that the metal will bend at
_a_, providing the heat is uniform. If, therefore, bending is required
at a certain place, that place should rest on the anvil and the blows
should be delivered beyond it.

After the first end has been bent to the required radius, the other
should be bent by holding it in the manner shown in Fig. 28, because
the joint of the tongs will prevent its being struck out of them while
the blow is being delivered. When both ends have been bent to the
proper radius, the ring should be finished as described in the ring
exercise (page 74), where upright blows are used with a leverage effect.


=50. The backing-up blows= are used to upset metal when it is
impossible to upset it in the usual manner, and in backing up the heel
of a scarf.

[Illustration: FIG. 29.—THE BACKING-UP BLOW, FOR UPSETTING.]

Upsetting with backing-up blows is done in the manner shown in Fig.
29. The metal should be extended over the anvil and thrust forward as
the blow is being delivered, to get the best results. This will also
prevent jarring the hand. The metal should be as hot as possible when
being upset in this manner.

The heel of a scarf is formed with backing-up blows after the metal has
been upset in the usual manner. The blows should be directed so that
they will have an upsetting effect, as indicated in Fig. 30, and not a
drawing one. After a few blows have been delivered with the face of the
hammer, they should then be delivered with the ball to form the heel
better and more rapidly.

[Illustration: FIG. 30.—BACKING-UP BLOWS USED FOR SCARFING.]


=51. The shearing blow= (see Fig. 31) is conveniently used for cutting
off small portions of metal instead of employing the hardy. It is
delivered so that the side or edge of the hammer will pass by and
nearly against the side or edge of the anvil. A blow so delivered will
have a shearing effect and cut the metal. It is perfectly proper to use
this blow for its intended purpose, but it should not be used when the
edge-to-edge blow is the one really required.


=52. Forging.=—Forging is the operation of hammering or compressing
metals into a desired shape. Seven specific operations are used.
Sometimes a piece of work or forging requires two, three, or even
all of them to complete it. These operations are designated by the
following names: drawing, bending, upsetting, forming, straightening,
twisting, and welding.

[Illustration: FIG. 31.—THE SHEARING BLOW.]


=53. Drawing=, the process of spreading or extending metal in a
desired direction, is accomplished by hammering or by pressing the
metal between such tools as the swages and fullers, or by holding it
on the anvil and using either of the set hammers, the flatter, or the
fuller. When using any of these pressing tools for drawing, a helper is
supposed to use the sledge to deliver the blows upon them.

It is always best to draw round metal with the swages, as it will be
smoother when finished than if it were done with the hammer; it should
be rolled in the swage a little after each blow of the sledge, and
after a complete revolution in one direction it should be turned in
the opposite direction, and so alternately continued until finished.
Especially if iron is being drawn, this will prevent twisting of the
fiber, which, if prolonged, would cause the metal to crack. Figure 32
shows the method of drawing with the swages.

When drawing any shape or size of metal to a smaller round diameter, it
is best first to draw it square to about the required size, delivering
the blows by turns on all four sides, then to make it octagonal, and
finally round. The finishing should be done with the swages, if those
of proper size are at hand; if not, light blows should be used, and
the metal revolved constantly in alternate directions, to make an
acceptable shape.

[Illustration: FIG. 32.—DRAWING WITH THE SWAGES.]

[Illustration: FIG. 33.—DRAWING WITH THE FLATTER.]

Drawing with the top and bottom fullers, in the manner shown with the
swages (Fig. 32), ought to be done cautiously, as the metal decreases
in size so rapidly that there is danger of its becoming too small at
the fullered place before the operator is aware of it. When using the
top fuller alone, in the same manner as the flatter (Fig. 33), similar
precautions should be observed. If the metal is to be decreased between
two shoulders, the top fuller may be used to rough it out; but the
fuller marks should be distributed between the shoulders, until one of
the set hammers or the flatter can be used.

If the metal is being drawn and is held crosswise on the anvil, as
shown at _a_, Fig. 34, it will increase in length more rapidly than
it will in width, and if held lengthwise as at _b_, it will increase
more in width than in length. This is due to the fact that the anvil
is slightly convex on its face, so that it has the effect of a large
fuller.

[Illustration: FIG. 34.—DRAWING WITH THE HAND HAMMER.]

The most difficult drawing for the beginner is to form metal into a
square or hexagonal shape. To draw it into a square form, the metal
must always be turned either one quarter or one half of a revolution to
prevent its becoming diamond-shaped, and the blows must be delivered
equally on the four sides to prevent its becoming oblong. If it does
become diamond-shaped, it can be made square by delivering blows at a
slight angle on the corners and sides of its long diagonal as shown
at _A_, _B_, and _C_, Fig. 35. If it is but slightly diamond-shaped,
the method shown at _B_ will prove satisfactory, but if badly out of
square, the method at _A_ will be the best.

[Illustration: FIG. 35.—SQUARING UP A DIAMOND-SHAPED PIECE.]

In drawing the hexagonal form, the metal should be turned by sixths of
a revolution. If it becomes distorted, it may be forged with such blows
as are shown at _B_ and _C_; if held as at _A_, it would be marred by
the edge _e_.


=54. Bending= is the operation of deflecting metal from a straight line
or changing its form by increasing the deflection already present. Iron
of any cross-sectional shape can be bent, but some shapes are much more
difficult than others.

The easiest to bend is the round, the only difficulty being to prevent
the hammer blows from showing. If the metal is to be round in section
when finished, the work will not have a good appearance if the cross
section is oval at some places and round at others, and unless the
hammer blows are cautiously delivered this will be the result.

Bending metal of a square section at right angles with the sides is not
very difficult, but bending such a section in line with the diagonal is
quite difficult, because the edges are liable to be marred where they
rest on the anvil and where the blows are delivered. The best method of
making bends of this kind is to heat the metal only where the bend is
to be, and then to bend it by pressure or pulling, while the work is
held securely in the vise, hardy hole, or swage block. If the heating
cannot be confined to the desired space, all excessively heated parts
should be cooled.

Oval sections are easily bent through their short diameters, but in
bending through the long diameters, the same method should be pursued
as described above for bending the square section in the plane of its
diagonal. Further explanations for bending are given on pages 118-121.


=55. Upsetting= is the operation of enlarging metal at some desired
point or place. It is done by hammering, ramming, or jarring. When a
piece of metal is too long it can be shortened by upsetting, or when it
is too thin at a certain place it can be thickened by the same method.
This is done by having the metal hot only at the point or place where
the upsetting is required. It is frequently necessary to cool the metal
where the heat is not needed in order to confine the upsetting to the
desired place.

Upsetting is not a very difficult operation as long as the metal is
kept perfectly straight; otherwise the task will prove tedious and the
metal may break from the constant bending back and forth. Bending will
always take place, but breaking generally can be prevented by having
the metal hot when it is straightened. The greatest difficulty in this
respect will be experienced when operating on common wrought iron.

Upsetting by hammering is done by holding the metal perpendicularly on
the anvil or something solid enough to withstand the blows which will
be delivered upon it. Figure 36 shows this method.

[Illustration: FIG. 36.—UPSETTING BY HAMMERING.]

If the end of a bar is being upset, and the upsetting is supposed to
extend up through the bar for some distance, the heated end should be
placed on the anvil as shown in the figure, because the anvil will
slightly chill the end of the bar, and the upsetting will continue much
farther than if the blows were delivered on the hot end. Striking the
hot end with the hammer increases the diameter of the end excessively,
because the contact of the hammer does not have a tendency to cool the
metal.

[Illustration: FIG. 37.—“BACKING UP” METAL.]

Another method of upsetting with the hammer, which is called “backing
up” the metal, is shown in Fig. 37. This method does not upset the
metal so rapidly, because the force of the hammer blows jars the hand
and arm which hold the bar.

Upsetting by ramming or jarring is thrusting the metal forcibly against
some heavy object like the surface plate, the swage block, or the
anvil. Figure 38 shows upsetting by this process. This method is very
effective and is used mostly when the metal is long enough to be held
with the hands, as shown.

[Illustration: FIG. 38.—UPSETTING BY RAMMING.]


=56. Forming= is a term generally applied to the making of a forging
with special tools, dies, or forms. This process may include bending,
punching, and other operations.

Swages are used for forming. A block of steel with a depression of a
special design is known as a forming die; a number of other tools and
appliances may be used for forming, but it is needless to mention them
here.


=57. Straightening= is one of the most frequent operations. When metal
is being forged, the various blows have a tendency to make it crooked,
and if the work is supposed to be straight when finished, it should be
so.

[Illustration: FIG. 39.—_A_, STRAIGHTENING WITH THE HAMMER; _B_,
STRAIGHTENING WITH THE SWAGE.]

There is as much skill required to straighten properly a piece of metal
as there is to bend it. The most common method (_A_, Fig. 39) is to
hold the metal lengthwise on the anvil with the bowed side or edge
upwards, then to deliver the blows at the highest point of the bow. The
blows will be most effective at the point where they are delivered,
so they should be distributed in order to get the object perfectly
straight and to avoid making unsightly hammer marks.

If the metal to be straightened is round, or if it is flat with round
edges, it is best to use a top swage of the proper size and deliver
the blows on the swage as shown at _B_, Fig. 39. Then the surface of
the round or the edges of the flat stock will not show any marks. The
flatter or round-edged set hammer may be used in the same manner on
flat or square material.

[Illustration: FIG. 40.—STRAIGHTENING WIDE METAL.]

When wide pieces of flat metal are to be straightened edgewise, and
such blows as are shown at _A_, Fig. 39, are not effective, then the
blows should be delivered along the concave edge as shown in Fig.
40, and distributed as indicated by the dotted circular lines. Blows
delivered in this manner will stretch or lengthen the metal on the
concave edge and straighten it.


=58. Twisting= is the operation of rotating metal to give it a spiral
appearance. It may be done either hot or cold, as the dimensions of the
material may require. It is done by holding the material in the vise,
the hardy hole, or the swage block, and turning one end of it with a
pair of tongs or a monkey wrench as many times as may be required. The
twisting will be confined between the places where it is held with the
vise, and where it is seized by the tongs or wrench.

If the material to be twisted is heavy enough to require heating,
a uniform heat is necessary or the twist will be irregular, and, as
an artistic appearance is usually desired, this operation should be
carried out with that result in view.

[Illustration: FIG. 41.—_A_, METAL TWISTED WHILE HOT; _B_, METAL
TWISTED WHILE COLD.]

_A_, Fig. 41, illustrates a piece of 1/2-inch square stock that has
been twisted while hot. _B_ shows a piece of 1/2 × 1/8-inch material
that has been twisted cold.

Another difficulty met with in twisting a piece of metal is that of its
becoming crooked. It can be straightened by laying the twisted portion
on a wooden block and striking it with a wooden mallet. This will
prevent the corners from becoming marred. A good method of avoiding
this trouble is to twist the metal inside of a piece of pipe whose
inside diameter is equal to the diameter of the metal.


=59. Welding=, the most difficult operation in the art of forging, is
the process of joining two or more pieces of metal into one solid mass.

All the previous operations allow some time for thought; in welding,
the worker must determine instantly where each blow is to be delivered,
as the welding heat of the metal vanishes rapidly; therefore, he is
compelled to think and act very quickly.

A scientific analysis of a perfect weld shows that it consists of
several processes, and that each one must be perfectly executed. If any
of these operations are improperly done, the result will be a partial
failure; if they are essential ones, the weld may readily be considered
as totally unfit.


=60. The Material for Welding.=—This must be considered, because there
are different qualities in each metal to be operated upon, and some
metals can be worked more easily than others.

A cross section of a bar of iron viewed through the microscope is seen
to be made up of a great number of layers or fibers, called laminæ,
resembling the grain or fiber in wood. These were cemented together
in the process of rolling or welding in the mill where the iron was
manufactured, and are continuous through its length. This makes the bar
of uniform quality throughout.

In welding, these fibers are joined diagonally at the ends,
consequently the strength of the weld depends entirely on how closely
or perfectly this cohesion is made. Careful hammering at the proper
heat brings the fibers in as close contact as possible, squeezes out
the slag and scale, and therefore greatly assists in strengthening the
weld.

Iron is an easy metal to weld. To prove this, place two pieces of
iron in a clean, non-oxidizing fire, allowing them to attain a white
or welding heat; then place them in contact and notice how readily
they stick together, proving that iron is easily welded at the proper
temperature. But in order to make the contact thorough, the pieces must
be hammered. This shows that hammering is a secondary operation, and
that iron cannot be joined by either heating or hammering alone.

By a similar experiment with soft steel, you will notice that the
pieces do not adhere like iron. If borax is applied while they are
heating, then slight indications of adhesion will be noticeable. This
shows that borax, sand, or something of a like nature must be used in
welding steel. In this case hammering is not a secondary operation, but
an essential one.

A higher carbon or tool steel may be experimented upon, with nearly the
same result. The noticeable difference between the lower and higher
qualities of steel proves that the greater the quantity of carbon, the
harder will be the welding, and if the experiments were extended to
still higher carbon steels, it would be discovered that they could not
be joined except by the use of a specially prepared flux. There are
indeed some high carbon steels that cannot be welded.

If a forging is to be made of a special quality of material, it is
frequently advisable to avoid welds, because two pieces that are welded
can hardly be considered so strong as a piece of the same material that
has not been welded.

The weldings which are alluded to here are such as are used by
practical blacksmiths in their general work without any special
appliances or apparatus whatever. The majority of the exercises on
welding in this book require the use of iron; for this reason this
preliminary consideration of metals need not have any further special
attention.


=61. Heating.=—When the word “fuel” is used here, either coal or coke
may be meant. Coal is the original in either case, for coke is formed
from it by the removal of gaseous substances. It is better that the
coal first be converted into coke, and that only the coke should come
in direct contact with the heating metals.

[Illustration: FIG. 42.—SECTIONAL VIEW OF A BLACKSMITHING FIRE.]

Figure 42 shows a sectional view of a blacksmithing fire: _d_ is the
bed of hot coke; _c_ is the dampened and unburned coal which surrounds
the fire, continually forming more coke as it is needed and also
holding the fire in a compact form; _a_ shows the proper way of placing
the metal in the fire, _b_, the improper way because the metal is
too near the entrance of the blast. As heating is such an important
operation, a thorough understanding of what causes imperfect heats, as
well as how to prevent them, is necessary.

The best fire for perfect heating is a reducing one, that is, one in
which the combustion of the fuel is rapid enough to use entirely the
oxygen in the air which is supplied. An oxidizing fire is one that does
not use all the oxygen in the blast for the combustion of the fuel.
The surplus oxygen will produce, on the surface of the metal, oxide of
iron, or a black scale, which is extremely injurious. This scale will
prevent welding, so all possible precautions should be taken to avoid
its forming.

A reducing fire can be maintained, and an oxidizing one avoided, by
having plenty of fuel surrounding the metal, equally, and allowing
the entrance of only sufficient air or blast to provide the necessary
heating.

If a piece of metal is left in a fixed position while heating, the
lower side will become the hottest. For that reason, all metals to be
welded are placed with scarfs downward. If the required heat is to be a
penetrating and thorough one, the metal is turned frequently to bring
all surfaces in contact with the most intense point of heat.

Even though every possible precaution is taken in all other steps of
the welding, the pieces cannot be joined perfectly if the heating is
carelessly done.


=62. Scarfing.=—This is the operation of preparing or shaping metal for
welding. There are five general kinds of welds, the distinct form of
each depending either on the quality of the material or on the shape of
the desired forging. They are called the lap weld, the cleft weld, the
butt weld, the jump weld, and the V weld.


=63. The lap weld= (Fig. 43) is so called because the pieces lap over
each other when placed in contact. It is most commonly used in general
practice, and all welds formed in a similar manner belong to this
class, regardless of the sectional form of the material or the shape of
the completed weld.

[Illustration: FIG. 43.—LAP WELD SCARFS.]

The pieces should always be upset where the scarfs are to be formed, to
provide excess metal for welding. They should be formed with their end
surfaces convex, and at an angle of about 45 degrees, which would not
make the joining surfaces too long.

When the fire and all tools are ready, place both scarfs face down in
the fire; when they are removed to the anvil, the piece held in the
right hand should be turned face up and rest on the anvil, in order
that the other may be placed in position on top of it.

The left-hand scarf should be placed carefully, with its point
meeting the heel of the other. If placed too high and overlapping,
it will increase the surface to be welded and perhaps decrease the
dimensions of the material where the points are welded down upon the
exterior. If placed too low, in all probability the surplus metal
provided by upsetting will not be sufficient to form the weld to a
uniform dimension. A little practice with the scarfs before heating is
advisable to prevent this difficulty.

The hand hammer should be placed conveniently on the anvil, with the
handle projecting sufficiently over the heel so that it can be grasped
quickly with the right hand as soon as the two pieces are in position.
If this precaution is not taken, the welding heat may disappear before
any blows can be struck.

The first blows after the pieces are placed should be directed toward
the center of the scarfs; when the center has been thoroughly united,
the blows should be directed toward the points to complete the
operation, if this can possibly be done in one heating.

It is impossible to give an invariable routine of blows; those given
are sufficient for the beginning, the rest must be left to the
observation and skill of the operator. Practice and judgment will
determine where the blows should be delivered, and when they should
cease.

As the welding heat vanishes very rapidly, it requires careful judgment
to determine when the pieces cease to unite. All blows delivered
after this will reduce the dimensions of the metal; if reheating
is necessary, there should be no metal sacrificed by unnecessary
hammering. Welds are generally weaker than the metal from which they
are made; consequently if the stock is made smaller at the weld, its
strength is greatly decreased.

The old adage “Haste makes waste” does not always apply. If you hasten
the operation of welding while the pieces are sufficiently hot, you
will not waste the metal. If through want of haste you are compelled to
reheat, you will waste metal, for every time a piece is heated it loses
a fractional part of its area, regardless of any hammering.

Welds made with scarfs of this kind are considered to be nearly as
strong as the metal itself, because they allow of a more thorough
lamination by hammering than other welds, consequently they are
frequently used on various qualities of metal when strength is
considered a chief requirement.

[Illustration: FIG. 44.—_A_, CLEFT WELD SCARFS; _B_, BUTT WELD SCARFS.]


=64. The cleft weld= (_A_, Fig. 44) is so called because one piece of
metal is split to receive the other. It is used for welding iron to
iron or steel to iron (the inserted portion being the steel). Whatever
the metal, the inserted portion is usually roughened with a hot cutter
on the pointed surfaces and the cleft hammered down and securely fitted
before the whole is heated. The pieces should not be placed in the fire
separately, but together, as they have been fitted.

When a welding heat appears, if possible, light blows should be
delivered on the end of the inserted portion while the two are in the
fire; these blows will partly join the pieces and make them secure
before removal. If this cannot be done, the first blows after removal
from the fire should be on the end. When a final and thorough welding
heat has been attained, they should be removed to the anvil and
securely joined. If heavy pieces are being operated upon, they may be
welded with the steam hammer.


=65. The butt weld= (_B_, Fig. 44) is so called because the pieces are
butted together and almost thoroughly joined by ramming or backing-up
blows before any blows are delivered on the exterior surface. The
scarfs are easily formed. The outer edges of the pieces are backed up
to form a rounded or convex end to insure their being joined at the
center first. As the blows are delivered on the end, the metal will
upset and the pieces will be joined from the center to the outer edges.
After they have been quite thoroughly joined with these blows, they
should be hammered on their exterior to weld them securely.

When scarfed in this manner, the pieces are frequently placed in the
fire for heating with the ends in contact, then partly joined while in
the fire and removed to the anvil or the steam hammer for final welding.

[Illustration: FIG. 45.—JUMP WELD SCARFS.]


=66. The jump weld= is shown in Fig. 45. The scarfs require perfect
forming, because the opportunity for hammering is limited, as blows
can be delivered only at certain places: on the end of the scarf 1
driving it into the concave groove 3; on a fuller which is held in the
fillet 4; and on both the edges indicated at 3.

The groove at 3 should be formed with sufficient metal at points 0, to
meet the projections _X_, and form a fillet. The convex scarf 1 should
first come in contact at 3, so that welding will proceed from that
place.

Welds made in this way are considered the weakest of those here
described, on account of the limited assistance which can be provided
by hammering. Still they are frequently used to avoid the laborious
operations required to make such forgings out of solid metal.

[Illustration: FIG. 46.—V WELD SCARFS.]


=67. The V weld= (Fig. 46) is a very important but difficult one. It is
generally used on extremely heavy work, such as locomotive frames (Fig.
47), beam straps, rudder stems, and all cumbersome forgings.

The process is as follows: Pieces 5 and 6 are to be welded. They are
held in a rigid position with heavy straps and bolts, as shown on the
locomotive frame in Fig. 47, sometimes while the V-shaped opening
is being formed; however, they must always be held secure while the
welding heat is being obtained. The V-shaped opening formed by the
scarfs on 5 and 6 should penetrate about two thirds of their thickness
and form an angle of about 50 degrees, with sufficient metal at _9_ to
provide for the waste which will occur while a welding heat is being
procured.

The wedge 7 is formed with some surplus metal for filling the V-shaped
opening. It is handled by a bar which is welded to it. The angle of the
wedge should be not less than 5 degrees smaller than the angle of the
opening. This will insure that the welding proceeds from the apex or
point of the wedge outward.

Two fires are required; 5 and 6, securely strapped and bolted together,
are placed in one with the V-shaped opening turned downward. Plenty of
coke is placed around this opening, completely covered with moistened
coal, and securely packed with a shovel; then two openings or vents are
made through the coal with a poker, one on each side of the metal and
leading to the scarfs. This is called a covered fire. The blast is now
turned on and slowly increased until the proper heat is attained. The
progress of heating can be observed through the openings thus made, and
the fire replenished with coke when necessary.

These operations are supervised by the smith who has the work in
charge, with two or more helpers or assistants, according to the size
of the forging. The wedge 7 also is heated in a covered fire with only
one opening on the workman’s side of the forge; the wedge is inserted
in that opening, and is attended and handled by another smith, who
watches its progress in heating.

When the supervising and attending smiths have signaled to each other
that the heats are ready, 5 and 6 are removed, turned over, and placed
on the anvil or on the steam hammer die to receive the wedge which is
placed in position by the attending smith. After the wedge has been
thoroughly welded into place with either sledges or steam hammer, the
handle and all surplus metal surrounding the openings are removed by
the aid of hot cutters and sledges.

This procedure must now be repeated and another wedge welded into place
on the opposite side indicated by the broken lines. With these two
wedges 5 and 6 will be securely joined.

To insure a perfect weld, a good quality of material should be selected
for the wedges. It should be thoroughly hammered to produce good
texture, and if iron is operated upon, the fiber of the wedges should
run parallel to the fiber of the piece to be welded. As this is not
generally observed, welds of this character often break through the
centers of the two wedges.

[Illustration: FIG. 47.—A BROKEN LOCOMOTIVE FRAME.]

The broken locomotive frame shown in Fig. 47 would be repaired by the
above method. The irregular line at _A_ shows where the break has
occurred. The straps and bolts at _B_ indicate the method of holding
the parts in alignment. Two tie rods at _C_ prevent the parts from
separating.


QUESTIONS FOR REVIEW

  What effect is produced by the upright blow? By the edge-to-edge
  blow? By the overhanging blow? By the beveling or angle blow? By the
  leverage blows? What are the backing-up blows used for? The shearing
  blows?

  What is meant by forging? How many different operations are used
  in forging? Name them. What is meant by drawing? What tools may be
  employed in drawing metal? If you desire to increase the length more
  than the width, how should you hold the metal on the anvil? Why? What
  precaution should be observed in revolving metal when it is being
  drawn into a round form? What is meant by bending? Can iron of any
  sectional shape be bent? Which is the easiest to bend? What shapes
  are difficult to bend? How are these difficulties overcome? What is
  meant by upsetting? Explain how it is done. What difficulty is often
  experienced in upsetting? What is the difference in effect between
  resting the heated end on the anvil, and striking on the heated end
  while upsetting?

  What is meant by forming? What other operations may be involved? What
  special tools or appliances are sometimes used for forming? State
  what has been said about straightening? Does it require much skill?
  Would it be as easy to straighten a wide flat piece of metal, as it
  would a round one? Why? Explain the operation of twisting. Why is it
  generally done? How can twisting be done and keep the work perfectly
  straight? Explain the essential parts of a weld. Is a weld as strong
  as the original unwelded bar? Can all iron and steel be welded? What
  kind of fire is best for heating? What is meant by an oxidizing
  fire? What effect does it have on the metal? How can an oxidizing
  fire be prevented? How should scarfs be placed in the fire? Why? If
  a penetrating and thorough heat is desired on a piece of metal, how
  can it be obtained? What is meant by scarfing? Are all scarfs formed
  alike? Name and describe the different kinds of scarfs and welds.
  Which one is considered the weakest? Why? On what kind of work is the
  V weld used?



CHAPTER III

PRACTICE EXERCISES


=68. Staple.=—Fig. 48. Drawing and bending. Material required: 5 inches
of 1/4-inch round iron.

[Illustration: FIG. 48.—STEPS IN MAKING A STAPLE.]

Draw 1 inch of each end to a flat chisel-shaped point 1/4 inch wide;
these drawn ends should be 1-3/4 inches long, leaving 3 inches of round
stock between them. Heat the center and bend it, with points edgewise,
to a semicircle of 3/4 inch inside diameter. These ends should be of
equal length, parallel and straight.

When drawing the ends, heat the metal to a white heat to prevent
the fibers from splitting or separating. Heat only to a cherry
red for bending, to prevent heavy scaling, which is one cause of
rough-appearing work. Rough work may also be caused by improper use of
the hammer in striking too hard or frequently at one place. (See Fig.
48 for dimensions and stages.)


=69. Draw Spike.=—Fig. 49. Bending and drawing. Material required: 7
inches of 1/4-inch round iron.

[Illustration: FIG. 49.—STEPS IN MAKING A DRAW SPIKE.]

Bend 3-1/4 inches of one end nearly to a right angle; have the inner
corner almost sharp and square, the outer portion circular at the
corner. Then form a perfectly circular eye of the 3-1/4-inch end,
having the center of the eye in line with the central portion of the
stem. When drawing the point, first draw it square, then octagonal, and
then finish it to a round. (See Fig. 49 for dimensions and stages.)


=70. S Hook.=—Fig. 50. Drawing and bending. Material required: 5 inches
of 1/4-inch round iron.

Draw 1/2 inch of each end to a smooth, round point; this should make
the length from point to point 6-1/4 inches, and the central portion
for 4 inches should be full-sized 1/4-inch round. Using half of the
entire length, bend the first hook to an inside diameter of 7/8 inch,
then bend the remaining half in the opposite direction to the same
diameter, bringing both points directly toward each other, as shown.
When heating for bending, be careful to avoid burning the points. (See
Fig. 50 for dimensions and stages.)

[Illustration: FIG. 50.—STEPS IN MAKING AN S HOOK.]


=71. Pipe Hook.=—Fig. 51. Upsetting, forging, and bending. Material
required: 9 inches of 1/2-inch square. Norway iron or soft steel is
best for this exercise.

(_Caution._ To avoid injuring the fiber of the metal and to upset it
rapidly with the least amount of labor, always have the metal perfectly
straight, and heat it only where the upsetting is required.)

Bring 4 inches of the central portion of the material to a white heat;
if the heat extends beyond that distance, cool 2-1/2 inches of each
end, then the upsetting will be confined to the desired place. Cool
the ends quickly and thoroughly, so that the upsetting blows may be
delivered before the heat has vanished. The material should be held
vertically with the lower end resting on the anvil, while heavy blows
are delivered on the top end, thus upsetting the heated metal.

[Illustration: FIG. 51.—STEPS IN MAKING A PIPE HOOK.]

These operations should be repeated until the center is 7/8 inch thick
one way, with all excess metal forged on one side, as at _a_, and
the three others perfectly straight. Now form a shoulder _b_, with
overhanging blows, about 1/8 of an inch from the center or thickest
portion, but draw it no smaller than 5/16 of an inch at the bottom.
Then draw the metal marked _c_ to an approximate dimension of 1/2 ×
5/16 inch. Form this shoulder perfectly square, by holding it over a
square corner of the anvil and delivering backing-up blows on the heavy
end, while the drawn part rests flat on the anvil; the metal should
be hot at the shoulder and cold on the end where the blows are to be
delivered. Then use the flatter on the drawn end to smooth and draw
it to the finished dimensions of 1/2 × 1/4 inch, making it perfectly
smooth and straight on all sides. Cut off this drawn end 6 inches from
the shoulder, as shown at _d_.

Draw the heavy end to a sharp, square point, making it straight on the
side opposite to the shoulder and tapering from a point about 2-1/4
inches from the shoulder; this should also be made smooth with the
flatter. Sketch _e_ shows this so far completed.

Beginning 1/2 inch from the shoulder, bend the 6-inch end backward
through its smallest dimension, to a semicircle of 3 inches inside
diameter. An outline of the required semicircle should be inscribed
on a plate, or models may be made to verify it. Sketch _F_ shows the
completed hook.


=72. Gate Hook.=—Fig. 52. Drawing, bending, and twisting. Material
required: 7-1/4 inches of 3/8-inch square mild steel.

Mark lightly with the hardy on two edges 1-1/2 inches from one end,
as shown at _a_. Form shoulders at these marks on three sides of the
metal; do not make them too deep, as surplus metal will be required for
bending here. Draw the metal at the shoulders just made, continuing to
the end to 5/16 inch round and 2-1/2 inches long. Sketch _b_ shows the
work completed to this point.

Mark the opposite end on the same edges and in a like manner 4-1/2
inches from where the first shoulders have been formed; form shoulders
at these marks and also draw down to 5/16 inch round, making the
extreme end a smooth, round point, 2-1/2 inches long from the
shoulders, as at _c_. Both of these ends should be round and smoothly
drawn with the hand hammer.

[Illustration: FIG. 52.—STEPS IN MAKING A GATE HOOK.]

Bend the straight, round end from the side _e_ to a right angle,
proceeding as follows: When placing the work on the anvil, have the
side _e_ uppermost and the shoulder projecting over the edge of the
anvil the thickness of the round, or 5/16 inch; then when the metal
is bent, the inside corner will be formed at the proper place and
the shoulder will readily form into a right angle on the outer side.
Light upright and backing-up blows will aid in forming the right angle
after it has been bent, provided the piece is held with the round end
vertical and resting on the face of the anvil. If such blows are used
while it is being held over the edge of the anvil, they will reduce
the sectional dimensions and not materially aid in forming the angle.
Sketch _d_ shows this angle in solid lines. Now form the round portion
of this angle into a circular eye, making the inside diameter 1/2 inch,
with the center on a line with the center of the main stem. Sketch _d_
shows this eye in broken lines.

Bend the pointed end in the same manner and in the same direction as
the eye, having the distance between the eye and the angle 4 inches,
as shown in sketch _F_. Now heat this end and cool the extreme corner
of the angle to prevent its straightening, then form the hook to the
dimensions given in the sketch.

Heat the central portion of the square metal to an even cherry red;
hold the hook and 1 inch of the square portion securely in the vise;
then grasp the other end with the tongs or wrench 2 inches from the
vise, and revolve it once, thus forming a twist of the proper length.
Before cooling this work, see that the eye and hook are parallel and
the body of the hook is perfectly straight.


=73. Door Hasp.=—Fig. 53. Drawing, forging, punching, cutting, and
bending. Material required: 7 inches of 1 × 3/16-inch mild steel.

Mark lightly with the hardy on the edges 1 inch and 3-1/4 inches from
one end, as at _a_. Form shoulders at these marks with edge-to-edge
blows, as shown at _b_, so that the metal between them may be drawn
to smaller dimensions. The shoulders should be formed not deeper than
1/8 inch at first, and the metal between them should be drawn to a
corresponding dimension. Then forge the 1-inch end into a round eye, as
at _c_, and punch a 5/16-inch hole in its center, as shown at _d_. Now
draw the metal between the eye and the shoulders to exact dimensions, 3
inches long, 5/8 inch wide, and 3/16 inch thick, as shown at _d_.

[Illustration: FIG. 53.—STEPS IN MAKING A DOOR HASP.]

Mark the other end in the same manner 2-1/2 inches from the shoulders,
and form new shoulders at these marks with edge-to-edge blows. Draw
the metal to a length of 2-1/8 inches, making it 5/8 × 3/16 inch at
the shoulders and 1/2 × 1/8 inch at the end; the extreme end should be
forged round. Sketch _E_ shows these operations completed.

Locate the center of the 2-1/2-inch length; from that point place
a center-punch mark 7/8 inch each side of the center and punch a
5/16-inch hole at each mark with a hand punch, by placing the outer
edge of the punch at the center-punch mark. Deliver no blows on the
edges of this metal after the holes are punched.

Using a sharp, hot cutter, remove the metal between the holes, by
cutting it equally from both sides, thus forming the slot as indicated
by the broken lines in sketch _E_. By placing it over the hardy,
straighten the metal which forms the sides of this slot, and all other
portions, so that all edges will be straight and parallel to each
other. Smooth all flat surfaces with a flatter, using water to remove
the scale of oxide. If the marking and punching of the holes have been
carefully done, the inside length of the slot will now be 2 inches.

Bend the 2-1/8-inch end to a right angle at the shoulders, having the
length from the inside of the angle to the outside of the eye about 7
inches. Heat this entire end and quickly cool the extreme corner of
the angle to prevent its straightening there, then form the hook to
the dimensions given in sketch _F_. The inner edges of the slot may be
filed straight and parallel to the outside edges, but the semicircular
ends which have been formed by the punch should not be disturbed.


=74. Hexagonal Head Bolt.=—Fig 54. Upsetting and forging to a hexagonal
cross section. Material required: 7 inches of 1/2-inch round iron.

Heat one end to a white heat, then cool off 4-1/2 inches of the
opposite end, thus confining the upsetting to the required area; upset
the hot end until its diameter is 3/4 inch, and the length over all is
about 5-1/2 inches.

It is important that the 4-1/2 inches be kept perfectly cold, to
prevent upsetting there, also to prevent its sticking fast in the
heading tool, or possibly using more metal than is required for forming
the head.

[Illustration: FIG. 54.—HEXAGONAL HEAD BOLT.]

The upset metal should extend equally around the bolt. This will tend
to prevent the head from forming unequally when the metal is being
forged down on the heading tool. The head can be prevented from forming
on one side by directing the blows toward the opposite side. Form
the head by heating the upset end to a white heat, by inserting the
opposite end in the heading tool, and by delivering upright blows on
the heated end, unless others are required, thus forging down the upset
metal to 1/2 inch thick. Remove it from the heading tool and forge the
head into a hexagonal form. It will be necessary to insert the bolt in
the heading tool several times to obtain the exact dimensions of the
head, which should be 7/8 inch through its short diameter and 1/2 inch
thick. The chamfered finish on the top of the head is produced by using
a button head set while the bolt is held in the heading tool.


=75. Square-cornered Angle.=—Fig. 55. Upsetting, chamfering, and
forging a square corner. Material required: 10 inches of 1 × 1/2-inch
iron.

Upset the center by cooling 3-1/2 inches of each end to confine
the operation to the required place. The center should be 7/8 inch
thick, and all upset metal should be forged to one side; the opposite
side and both edges should be straight. Draw both ends tapering from
where the upsetting ceases to 3/4 × 1/4 inch at the ends; chamfer the
edges of the drawn ends on the straight, flat side, beginning about 2
inches from the center and continuing to the ends. If the drawing and
chamfering are properly done, each end will be 5-1/2 inches from the
center.

[Illustration: FIG. 55.—UPSETTING FOR A SQUARE CORNER.]

Heat and bend the stock at the upset center to a right angle, with
the upset metal on the outer side to provide for the square corner.
The bending should be done over the horn of the anvil to produce the
quarter-round fillet on the inner side, and may be confined to the
center by cooling both ends to where the upsetting begins.

As bends of this kind are somewhat difficult to make correctly, it
would be a great advantage to provide a form which may be made to fit
into the vise; then one end of the angle can be held securely with the
form while the opposite end is bent over it. By any simple form it is
impossible to make the outside corner perfectly sharp and square with
one operation; it is therefore necessary to forge the outside corner
sharp and square by delivering blows on both sides, somewhat in the
manner shown in Fig. 56, but good judgment must be used in doing this.

[Illustration: FIG. 56.—SQUARE-CORNERED ANGLE.]

The chamfering may be marred or entirely removed in forging the corner;
if so, rechamfer, and if the ends are of unequal lengths, the longer
one should be cut off equal with the other. Then all surfaces should
be made straight and smooth with the flatter and the scale removed by
occasionally dipping the flatter in water.


=76. Fagot Welding.=—Welding and forging to dimensions. Material
required: convenient pieces of scrap iron and a bar of 5/8-inch round
stock from 24 to 30 inches long.

Temporarily weld several separate pieces of scrap on to the bar until
sufficient metal is provided for a thorough welding and forging of a
solid piece of square iron 3-1/2 inches long and 11/16 inch square. The
welding should be done so as not to show where the pieces were joined.
Forge it perfectly square and smooth with the flatter. Cut one end off
square with a sharp hot cutter, then cut it to the required length.


=77. Round Weld.=—Fig. 57. Scarfing, welding, and swaging. Material
required: two pieces of 7/16-inch round iron, 4-1/2 inches long.

Upset one end to 9/16 inch, as shown at _a_. To form the scarf, deliver
backing-up blows with the face of the hammer, as shown at _b_, and
finish with blows delivered similarly with the ball. These backing-up
blows will form the heel of the scarf. Draw out the point of the scarf
with overhanging blows, as shown at _c_. The joining surface should be
convex so that welding will proceed from the center. Scarf both pieces
in the same manner, as at _d_.

[Illustration: FIG. 57.—STEPS IN SCARFING FOR A ROUND WELD.]

Heat and weld according to instructions on welding and finish the work
smoothly with swages; then cut to a length of 6 inches, having the weld
in the center.

Properly formed scarfs will produce perfect welds provided they are
heated to the welding temperature when they are joined, but those
improperly formed generally produce imperfect welds, although the heat
is right.


=78. Flat Right-angled Weld.=—Fig. 58. Material required: two pieces of
iron 3/4 × 3/8, 4-1/2 inches long.

Upset one end 1/8 inch larger than its diameters, as at _a_. By using
backing-up blows as in the previous exercise, form a heel on one
side, as shown at _b_, then resting the straight side on the anvil,
draw out the point with the ball of the hammer, as at _c_. In drawing
this point, the metal will spread and form a wide fan-shaped end, but
by resting the right side _d_ on the horn of the anvil and delivering
blows on the left, the latter edge will be straightened, leaving all
projecting metal on the right.

[Illustration: FIG. 58.—STEPS IN SCARFING FOR A CORNER WELD.]

Upset one end of the other piece to the same dimensions, allowing this
upsetting to continue along the metal about 1 inch. Form a scarf on the
left edge at _e_, with the ball of hammer, using blows similar to those
shown at _c_ and leaving the end square. Place them together to see if
the points meet the heels; if not, make necessary alterations so they
will.

Place the pieces in the fire, so that the side scarf will be removed
with the left hand and the end scarf with the right. When placing for
welding, the right-hand piece should be laid on the anvil and the
left-hand one placed in its proper position on top of it. The inside
corner should form a quarter-round fillet, the outside should be sharp
and square, and the longer end cut off to make them both equal. Smooth
all surfaces with a flatter. Sketch _F_ shows the weld completed; the
dotted lines indicate the location of the scarfs before welding.


=79. T Weld.=—Fig. 59. Scarfing and welding. Material required: two
pieces of 3/4 × 3/8-inch iron, 8 and 4-1/2 inches long.

[Illustration: FIG. 59.—STEPS IN SCARFING FOR A T WELD.]

Upset one end of the shorter piece 1/8 inch larger than its diameters,
and form a scarf similar to the first one for the right-angled weld,
but here allow it to form fan-shaped and project equally over each
edge, as shown at _a_.

Upset the center of the long piece to 1/8 inch or more larger than its
diameters, with the upset portion fully 1 inch long, as at _b_. Form a
scarf at this place with the ball of the hammer, allowing the metal to
bend edgewise, as at _c_. Do not make this scarf quite so wide as the
first one, as its edges should be entirely covered by scarf _a_ without
leaving any openings. See that they fit properly before heating for
welding.

Especial care should be taken to have a good fire. The long piece
should be placed in the fire so as to be removed with the left hand,
and the short one with the right. Place the short piece on the anvil,
with the long piece, held in the left hand, on top of and overlapping
it sufficiently to prevent any openings. When welded, the long piece
should be perfectly straight, with the short one at a right angle to
it. Finish the weld with the flatter while it is at a dull red heat.
Sketch _D_ shows the T completed.

[Illustration: FIG. 60.—CHAIN MAKING.]


=80. Chain Making.=—Fig. 60. Bending, scarfing, and welding links.
Material required: 8 pieces of 3/8-inch round iron, 6 inches long.

Heat and bend the center of each piece to a semicircle 3/4 inch
inside diameter; make the ends of equal length and parallel from
the semicircle, as at _a_. Take one of these bent pieces and form a
scarf on one end by holding it on the edge of the anvil at an angle
of 45 degrees, as shown at _b_, and delivering overhanging blows, as
indicated by the dotted circle, which represents the hammer. Turn the
link over, placing the other end in the same position as the first, and
scarf. Bend both scarfs toward each other equally until they overlap
sufficiently to prevent any opening being formed, as at _c_; this is
called closing the scarf.

Heat and weld the link by delivering the first few blows on its sides
while it is resting on the face of the anvil, then by delivering
lighter ones, while it is hung on the horn. While striking the light
blows, do not hold the link in a fixed position, but move it to receive
the blows around the circumference. The finished dimensions are 2 ×
3/4 inches inside; a slight variation in length does not make any
difference, but their ends and widths should be uniform.

Proceed with another piece in like manner, but after scarfing it insert
the finished link and continue adding new ones, until there are five
links all together. The three extra pieces are for use in the next
three exercises.


=81. Welded Ring.=—Fig. 61. Bending, scarfing, and welding a ring of
round iron. Material required: one piece of 7/16-inch round iron, 8
inches long.

[Illustration: FIG. 61.—STEPS IN MAKING A RING.]

Heat, and bend over the horn of the anvil about 1-1/2 inches of each
end to an inside radius of no less than 1 inch, as at _A_. Then heat
the straight portion to a uniform temperature and bend it by holding
the piece in a vertical position on the anvil, and delivering upright
blows, as shown at _B_; this should produce a form similar to that
shown at _C_. Continue the bending by holding the work as at _D_. By
carefully observing the effect of these blows, you will be able to
determine how the work ought to be held to produce the complete ring.
These blows are used here to give the same effect as leverage blows.
If the position of the metal is changed when and where it should be,
almost a perfect ring may be produced without holding it on the horn
of the anvil. It is not the best method to hold the work on the horn,
because blows delivered in this way have a tendency to produce oval
sections where they hit. In forming this ring the ends should be left
open about 1 inch.

The directions for scarfing and welding are somewhat similar to those
given for links, except that the angle of the scarf should be nearly a
right angle. After the welding is completed, the ring should be made
perfectly round by placing it over a mandrel or the horn of the anvil.
When the ring is welded and complete, connect it to the chain with one
of the extra links.


=82. Chain Swivel.=—Fig. 62. Bending, scarfing, welding, and riveting.
Material: about 2 feet of 7/16-inch round iron. Norway iron is the
best, and this length is the most convenient for the first operations.

[Illustration: FIG. 62.—CHAIN SWIVEL.]

[Illustration: FIG. 63.—TOOL FOR WELDING A SWIVEL.]

For making this swivel, a special mandrel (Fig. 63) should be provided,
made of 3/4-inch round, mild or tool steel, with a short offset of 3/4
inch; the gudgeon or pin which is shown at _a_ should be 1-1/4 inches
long, 7/16 inch in diameter at the shoulder, and tapering to 5/16 inch
at the end. Any convenient length of handle that will prevent burning
the hand when welding, will do.

Bend about 2-1/2 inches of the 7/16-inch round stock to a right
angle, as at _a_, Fig. 64; make the corner as square as possible, by
upsetting it before bending; or after bending, by using upright and
backing-up blows. Flatten the bent portion _b_ parallel with the bar,
by first delivering the blows with the ball of the hammer to increase
the width as much as possible, then finish it to 3/16 inch thick with
the face of the hammer. The corner should be scarfed with the ball of
the hammer and the rib worked out, as shown at _c_.

[Illustration: FIG. 64.—STEPS IN MAKING A SWIVEL.]

Cut off the flat portion 2 inches from the bar, and form a thin scarf
at the end of _b_. Notice that this should be formed on the same side
with _c_. Beginning with the scarf at the end, the flat portion should
be bent or rolled up so that the scarfs will overlap considerably,
as indicated in the end view _d_. The special mandrel should now be
inserted in the opening shown here, and all placed in a 3/4-inch bottom
swage, while the scarfs are hammered into close contact.

The long bar should now be cut off 4-1/2 inches from the inside of the
bend, and a fan-shaped scarf formed with the ball of the hammer, as at
_e_. This should be drawn thin on the end and sides. The center of the
4-1/2-inch length is next bent and the last scarf placed in position
at _f_ by again inserting the mandrel, placing it in the swage, and
closing down the edges around the portions at _f_. It is then ready for
welding. Figure 62 shows this in solid lines.

[Illustration: FIG. 65.—MAKING AN EYE FOR A SWIVEL.]

A good clean heat should be procured for welding; the mandrel should be
quickly inserted, placed in the swage, and the welding done. This being
completed, a small eye is to be made of 3/8-inch round iron: first, by
bending it in the form shown at _a_, Fig. 65; second, by inserting a
punch in the opening and hammering the ends together, forming the eye,
as shown at _b_; third, by welding these ends solidly together, as at
_c_, and forging the whole to fit loosely in the swivel. The fitted end
is now cut off square 3/8 inch longer than the depth of the hole in the
swivel, heated, and, while the eye is held in the vise, it is quickly
riveted into place with a small straight or ball peen hammer. The eye
is shown in place by the broken lines in Fig. 62. Connect this swivel
to the chain with one of the extra links.


=83. Chain Swivel.=—Figs. 66 and 67. Fullering, forging, bending,
welding, and riveting. Material: a piece of 1 × 1/2-inch iron, 4 or
more inches long.

Using top and bottom fullers, form two sets of depressions not deeper
than 1/4 inch, on each edge and opposite to each other, the first pair
to be 1 inch from the end, the second pair 1 inch from the first, as at
_a_.

[Illustration: FIG. 66.—STEPS IN MAKING A SWIVEL.]

Draw the 1-inch end to 7/16 inch round, leaving it slightly heavier
where it was fullered to provide excess metal for further bending.
The opposite end should now be cut off 1 inch from the fullered place
and drawn to the same dimensions as the first end. Forge the central
portion into a circular form and punch a 3/8-inch hole in its center.
Cut off all surplus material, making the ends 3-1/2 inches long from
the center of the hole, as at _b_.

[Illustration: FIG. 67.—THE COMPLETED SWIVEL.]

Bend each end to a right angle close up to the eye and make the arms
parallel and one inch apart, as at _c_. Drift the hole by driving the
punch through between the parallel ends, thereby forming a slightly
tapered hole. Scarf and weld the ends as you would a link. Make a small
eye of 3/8-inch round stock, proceeding in the manner explained in the
previous exercise, also following the same instructions as to fitting,
cutting, and riveting. Connect the link end of this swivel to the chain
with one of the extra links. (See Fig. 67.)

[Illustration: FIG. 68.—STEPS IN MAKING A CHAIN GRABHOOK.]


=84. Chain Grabhook.=—Fig. 68. Forging, punching, and bending.
Material: one piece of 3/4 × 3/8-inch iron, 4-1/2 inches long.

Form a depression as at _a_, 1/4 inch deep and 3/4 inch from one end
with overhanging blows. (The opposite edge should be kept perfectly
straight during this and the following operations.) Forge the 3/4-inch
end into a circular-shaped eye 3/8 inch thick, and punch a 1/4-inch
hole, in the center, as at _b_. This hole should be drifted or expanded
with a punch driven through from both sides alternately until the
diameter becomes 1/2 inch.

By hanging this eye over the horn of the anvil so that the inner
corners of the eye rest on the horn, by delivering blows opposite to
those corners, and by changing its location so that blows will be
delivered on all outside corners, the sectional form will be changed
from square to octagon; by similar operations the form may be changed
from octagon to round. During this change, light blows should be used
in order to make the eye smooth. This stage is shown at _c_ with a
sectional view of the eye.

[Illustration: FIG. 69.—THE COMPLETED CHAIN GRABHOOK.]

Proceeding from the eye toward the opposite end, forge both edges round
to correspond with the eye, leaving the metal 3/4 inch wide, 3 inches
from the eye, as shown at _d_.

Draw the remaining section tapering from this extreme width to 1/4
inch, and forge the edges round as before. The hook should be 3/16
inch round at the end and 3 inches long from the widest point, as
shown at _E_. Heat the middle portion; cool the point and the eye, and
bend the hook edgewise over the horn of the anvil toward the straight
side, until the point is opposite the depression first formed. The
inside semicircle formed by bending should be 1/2 inch in diameter,
the other inside lines straight and parallel. The extreme point should
be slightly curved away from the eye, and all flat surfaces hammered
smooth with light blows while the hook is at a dull red heat. Figure 69
shows the hook completed. Using the remaining extra link, connect the
hook to the swivel.


QUESTIONS FOR REVIEW

  What forging operations are employed in making the staple and the
  draw spike? What hammer blows are used on them? What caution should
  be observed in heating the S hook for bending? What operations are
  employed in making the pipe hook? Which is the most difficult? Where
  was the most difficult forging encountered? How was the point drawn?
  What operations are employed in making the gate hook? Explain how
  the angle should be bent, and how the blows should be delivered to
  make it square. Why should the extreme corner of the angle be cooled
  off before bending the hook? What operations are employed in making
  the hasp? Which one is used first? Into what form is the metal to be
  forged in making the bolt? What is meant by chamfering? What kind
  of hammer blows should be used in chamfering? Why should the metal
  be upset for the round weld? What special hammer blows are to be
  used in forming the scarfs? Explain how the scarfs are formed for
  the right-angled weld. How should scarfs be placed in the fire? How
  should they be placed on the anvil? Explain how the scarfs are formed
  for the T weld. Describe the scarfing of a link. Describe the welding
  of a link. What is the effect of bending the ring over the horn of
  the anvil? What operations are used in making the chain swivel?



CHAPTER IV

TREATMENT OF TOOL STEEL


=85. Selecting and Working Steel.=—In making a tool, the differences
in quality of steel should be considered, because steel suitable for a
razor would not do for a cold chisel or any battering tool. (See sec.
181.)

If the steel at hand is not exactly suitable, but the selection must
be made from it, then that should be chosen which will most nearly
meet the requirements, and tempering must be relied upon to make up
the deficiency. In most large factories all grades of steel are kept
on hand and are assorted in the stock room so that there need be no
difficulty in making the proper selection.

The percentage of carbon in steel represents the amount of carbon it
contains. A steel that is called a 75-point carbon steel is one that
contains (.75) seventy-five one hundredths of one per cent, each point
representing (.01) one one hundredth of one per cent.

Some steel makers use the word “temper” to indicate the amount of
carbon, expecting the user of the steel to be familiar with the
amounts of carbon each different temper represents. For instance, a
razor-temper steel represents one that contains 1.50 per cent carbon
and a tool-temper steel represents one containing about 1.25 per cent.
The word “temper” as used in this connection should not be confused
with the word as it is used in the art of tempering, where it
indicates the operation of reducing the hardness of the metal in order
to make it less brittle and more suitable for some particular use.


=86. Uses of Different Grades of Steel.=—As the percentage of carbon,
and consequently the quality of steel, will vary somewhat with
different makes, it is rather difficult to give a rule that will
apply generally, but the following list of different grades of carbon
will give a general idea of how steel should be selected, forged, and
hardened.

Steel of 0.7 to 0.8 per cent carbon should be used for snaps, rivet
sets, cupping tools, etc. This grade of steel should be forged at a
light red heat. It can be welded easily and will harden at a light red
heat.

Steel from 0.8 to 0.9 per cent carbon should be used for drop-forging
dies, hammers, cold sets, track chisels, blacksmith’s tools, well
drills, etc. It should be forged at a light red heat; it welds easily
and hardens at a light red heat.

Steel from 0.9 to 1 per cent carbon should be used for large hand
chisels, large punches, shear blades, dies, etc. Forging should be done
at a light red heat. It welds readily and hardens at a bright red heat.

Steel from 1 to 1.1 per cent carbon should be used for hand chisels,
punches, punch dies, small shear blades, etc. Forging should be done at
a light red heat. It welds readily and hardens at a bright red heat.

Steel from 1.1 to 1.2 per cent carbon should be used for screw-cutting
dies, large cutting and trimming dies, small punches, small hand
chisels, large milling cutters, cups, cones, etc. Forging should be
done at a light red heat. It welds readily when care is taken in
heating, and hardens at a bright red heat.

Steel from 1.2 to 1.3 per cent carbon should be used for drills, taps,
reamers, milling cutters, circular cutters, cutting and trimming dies,
mill picks, engraving tools, twist drills, etc. Forging should be done
at a bright red heat. Welding can be done when precaution is taken
against overheating and burning. It hardens at a dull red heat.

Steel from 1.3 to 1.4 per cent carbon should be used for small drills,
taps, cutters, boring tools, etc. Forging should be done at a bright
red heat; welding can be done with care against overheating. It hardens
at a dull red heat. This steel should be handled carefully.

Steel from 1.4 to 1.5 per cent carbon should be used for tools for
working chilled castings or locomotive wheel tires, lathe and planer
tools, razors, or any tools required to cut hard materials. Forging
should be done at a dull red heat. Welding can scarcely be accomplished
with this grade of stock. Hardening should be done at a dark red heat.


=87. Injuries.=—One of the most common injuries to steel comes from
carelessness in the heating for forging. It is one of the important
operations, for unless the metal is uniformly heated, violent strains
are liable to occur, and, when hardened, the steel will show these
strains by cracking. These defects are known as fire cracks.

The smith should always have plenty of fuel surrounding the metal while
it is in the fire so that the cold-air blast will not come in direct
contact with the metal. The air should be heated by passing through a
bed of hot coals before it strikes the steel. It is always necessary to
heat steel thoroughly to make it plastic, being careful not to overheat
or burn any part of the metal. If it is overheated or burned, it
cannot be completely restored to its former state; the grain becomes
coarse and the structure weak.

Never let steel lie in the fire to soak up heat after it is hot enough
to work. If for any cause it cannot be worked when it is ready, it
should be taken from the fire and left to cool, then reheated when it
can be worked. By this precaution injury to the steel will be prevented.

If steel is heated so that the outer parts are hotter than the center,
the metal will forge unevenly. The outer portion will be forged by the
hammer blows, while the center remains almost in the original form.
This will also cause an uneven grain, sure to produce cracks when the
tool is hardened. Forging at too low a heat will injure the steel in
the same manner as uneven heating.

After the steel has been properly heated, and forging has begun, the
first blows should be struck rather heavily and followed by lighter
ones as the heat vanishes. The forging should cease when the steel gets
too cold, but it may be reheated as often as necessary to complete the
work.


=88. Annealing.=—After the steel has been forged to the desired shape,
it usually is necessary to do some finishing upon it before it can be
hardened and tempered; in order to do this, it must be annealed or
softened so that it can be machined or filed into shape. _Annealing
is the process of softening steel._ It is done by heating the steel
slowly to an even low red heat and placing it in an iron box containing
unslaked lime or fine charcoal and leaving it there until perfectly
cold. The object of this process is to retain the heat and prolong the
cooling. The box is usually of cast iron, but sheet steel is equally
good. It should be placed in a perfectly dry place and rest on bricks,
if necessary, to avoid any dampness.

If an annealing box is not at hand, small steel forgings can be
softened very satisfactorily by placing them between two boards, then
completely covering all with dry ashes and leaving them there until
entirely cold. Precaution should be taken here, also, to leave them in
a dry place.

Another method, which is sometimes used, is called _water annealing_.
Some mechanics claim to have had good results with it, while others
condemn it entirely. By this method the article is heated to a dull red
and allowed to cool partly, out of any direct current of air. When all
redness has disappeared as it is held in a dark place, it is plunged
into water and left there until perfectly cold.

The first method mentioned above is always the best; the second is
nearly as good; and only when there is not sufficient time to allow the
metal to cool slowly, should water annealing be attempted.

Such tools as cold chisels and lathe tools may be heated and laid in
or on warm ashes until nearly cold, when they may be ground, hardened,
and tempered. Quite frequently, if not generally, these tools are not
treated in this manner, but it is no doubt the course to pursue to get
the best results.


=89. Hardening and Tempering.=—When steel has been properly heated,
forged, finished, or ground, the next two steps are hardening and
tempering. These two processes are often understood as one, but they
are entirely different in their results. The confusion arises because
the two operations are sometimes performed with one heating of the
steel as in hardening and tempering a cold chisel, or other similar
tools.

As the steel has been subjected to severe strains during the heating
and forging operations, its structure may have been somewhat altered.
It can be restored to the proper crystalline structure by the
hardening, scientifically known as refining. The hardening or refining
heat is always lower than the forging heat, and should be only as high
as is necessary to harden the steel to the required density by sudden
cooling. Then this first operation of cooling will harden and refine
the steel at the same time.

Extreme hardness is always accompanied by extreme brittleness, a
quality undesirable in any cutting tool, and especially so in a tool
required to withstand sudden shocks. As the hardness is reduced by
subsequent heating, the toughness increases. This modification, called
tempering, is accomplished by reheating the hardened portion of the
tool until a sufficient toughness has been obtained, when the process
is stopped by again plunging the tool into cold water. The heat for
tempering may be supplied from the uncooled portion of the tool as in
tempering a cold chisel, from the forge fire, from another hot piece of
metal, or from a carefully heated furnace.

It has been found that the colored oxides formed on the surface of a
piece of polished steel or iron represent a definite temperature in
that metal. These colors have been used, therefore, to determine the
desired temperature in tempering a tool. When we say “temper a tool to
a light straw,” we mean that the hardened tool is to be heated again to
a degree which will produce that color; namely, about 430 degrees Fahr.
The colors as they appear are light straw, dark straw, bronze, bronze
with purple spots, purple, dark blue. The light color appears first. Do
not allow the colors to pass too quickly, as will happen if the heat
applied is too intense.

[Illustration: FIG. 70.—HARDENING A CHISEL.]

There are two distinct methods of hardening and tempering. The one
generally followed in tempering cold chisels, lathe and various other
tools, requires only one heating. The tool is heated to a proper
hardening temperature at the end, where hardness is desired, and
also over an excess area to supply the heat for tempering. About 2
inches of the cutting end is heated; about 1 inch of this is plunged
perpendicularly into water, as shown in Fig. 70; it is then kept in
motion perpendicularly between the places indicated at _a_ and _b_,
while the end is cooling. This will prevent a fixed cooling point
and prevent a fracture that might possibly occur if it were held in
one position while cooling. The portion between _b_ and _c_ should
retain sufficient heat to produce the necessary temper. When the end
is perfectly cold it should be removed and immediately polished with
sandstone or emery cloth to remove the scale of oxide so that the
different colors may be more readily seen as they move from _b_ toward
the point. The heat in the portion between _b_ and _c_ flows toward
the point, causing the colors to appear as the heat extends. When the
desired color covers the point, it should again be plunged into the
water and left there until entirely cold. In this method the first
cooling is the hardening, and the second the tempering. A comparative
color chart is appended to this chapter for guidance in obtaining the
tempers for various tools.

[Illustration: FIG. 71.—HARDENING A REAMER.]

By the second method the steel is heated as in the first method,
then it is cooled off entirely by immersing the tool exactly
perpendicularly, as shown in hardening a reamer in Fig. 71; after this
it is polished. The temper is then drawn by holding the tool in contact
with a piece of heated metal, cast iron preferably. In Fig. 72 the
reamer is shown inside of a heated bushing, which is a more practical
way than laying it on top of a heated flat plate. The bushing will
impart sufficient heat to the tool to produce the desired color, when
it should be again cooled. This method is used mostly for tempering
plane bits, wood chisels, milling cutters, taps, reamers, and various
other tools of a like nature.

Sometimes tools having sharp protruding edges, as milling cutters,
taps, reamers, etc., are very liable to crack by the sudden cooling
in water; this difficulty is avoided by using oil for hardening and
tempering. Any so treated are called oil-tempered tools.

[Illustration: FIG. 72.—TEMPERING A REAMER.]

The above methods of tempering are such as are ordinarily used when
only a common shop equipment is at hand, and the operator must depend
entirely upon his judgment of the colors which represent the proper
forging, annealing, hardening, and tempering heats. The degree of
accuracy that has been attained in this practice is most surprising.

In large manufacturing establishments where many duplicate pieces
are to be tempered, a more modern as well as scientific apparatus is
employed to relieve the operator of dependence upon his discernment of
colors. Here the steel is heated in a furnace, to which is attached
a pyrometer that registers the exact degree of temperature. In this
manner all pieces can be heated uniformly for any of the four required
heats.

[Illustration: FIG. 73.—SECTIONAL VIEWS OF TOOL STEEL, SHOWING THE
EFFECTS OF PROPER AND IMPROPER TREATMENT.

  _A._ Natural Bar.
  _B._ Refined.
  _C._ Too hot.
  _D._ Burned.]

The views in Fig. 73 were photographed from the same grade or bar of
steel to show the various granular structures produced by different
heat treatments. _A_ shows the condition of the natural bar, which
was broken to be photographed just as it was received from the steel
makers. The lower left side shows where it was nicked with the cutter
to be broken. _B_ shows the structure when proper conditions of
heating and hardening have been maintained. Notice how much finer the
structure here appears to be; this effect was caused by, and previously
referred to as, the refining heat of steel. A similar condition should
be produced with any tool steel under correct treatment. _C_ shows
a much coarser structure; it was heated too hot and hardened in the
same manner. If a tool were made thus, its weakness would be hardly
noticeable at the time, but the structure shows that it is considerably
weaker. _D_ shows the condition of the stock after being burned. It has
produced from a quality of steel that was valuable, a metal worthless
for any kind of tool.


=90. Casehardening.=—Another method of hardening, called casehardening,
is used for wrought iron and low carbon or soft steel parts which are
to be subjected to considerable friction. Neither of these metals
could be hardened by the other methods mentioned. This process adds
carbon to the exterior surfaces only, and for that reason is called
casehardening, as the outside is made extremely hard, while the inner
portion or core remains in a condition like that produced by sudden
cooling, thus providing a hard wearing surface and great strength at
the same time. It is similar to the old cementation process of steel
making, but is not prolonged sufficiently to allow the hardening to
continue through the entire structure.

The articles to be hardened are packed in a box somewhat similar to
an annealing box. This should be partly filled with charred leather,
ground bone, or wood or bone charcoal, all of which are highly
carbonaceous materials; then the articles are placed in and entirely
surrounded with a thin coating of cyanide of potassium, especially if
iron is being hardened. The remaining space in the box is filled with
the leather, bone, or pieces of charcoal. The box should be provided
with a lid that will drop loosely between the outer projecting rims.
The outer edges of this lid should be luted with clay to keep it as
air-tight as possible. If a few small holes are provided in the center
of the lid, test wires can be inserted; by removing a wire and cooling
it, the progress of the operation may be known. These wires should
be inserted before the box is placed in the furnace. The box and its
contents are then placed in a suitable furnace and kept thoroughly
heated from 6 to 15 hours, depending upon the depth of hardness
required. Then it is withdrawn, the lid removed, and the articles
quickly plunged into a large tank of water. This will complete the
hardening.

When a number of very small articles are to be hardened, it is
advisable to connect them with strong bailing wire before they are
placed in the box so that they can all be removed at once. Beside
holding the articles together, the wire will provide a means of testing
the depth and quality of the process.

If only a thin coating of hardness is needed, or the labor and expense
are excessive, the following method may be used: The article is heated
thoroughly and evenly to about a bright red and thoroughly sprinkled
with, or rolled in, cyanide of potassium. Then it is reheated so that
the cyanide may penetrate as deeply as possible, after which it is
quickly chilled in cold water. This is a good method of hardening small
tack hammers made of soft steel, set screws, nuts, and very small tools.

  TEMPERATURE AND COLOR CHART TO BE USED IN TEMPERING
        Tools               Temperature (Fahr.)      Color
                                  _Degrees_
  Scrapers for brass                 430        Very pale yellow
  Light turning tools                430        Very pale yellow
  Lathe and planer tools for steel   430        Very pale yellow
  Steel engraving tools              430        Very pale yellow
  Milling and boring cutters         460        Straw yellow
  Screw-cutting dies                 460        Straw yellow
  Taps and reamers                   460        Straw yellow
  Punches and dies                   480        Dark straw
  Penknives                          480        Dark straw
  Twist drills                       500        Bronze
  Plane irons                        500        Bronze
  Surgical instruments               530        Dark purple
  Cold chisels for steel             540        Dark purple
  Cold chisels for cast iron         550        Dark blue
  Cold chisels for wrought iron      550        Dark blue
  Springs                            570        Very dark blue

  SUITABLE TEMPERATURE (FAHR.) FOR:
                                                _Degrees_
  Annealing tool steel                          900
  Forging tool steel                            1200 to 1500
  Hardening tool steel                          1200 to 1400
  Casehardening iron or soft steel              1300 to 1500

  COLORS AND CORRESPONDING TEMPERATURES (FAHR.) FOR IRON
  Bright red in dark                            750 to 760
  Red hot in twilight                           880 to 890
  Dark red hardly visible in daylight           970
  Red visible by daylight                       1070
  Brighter red by daylight                      1300
  Cherry red by daylight                        1450
  Bright cherry red by daylight                 1650
  Light cherry red by daylight                  1800
  Orange                                        2000
  Yellow                                        2150
  White heat                                    2350
  White welding heat                            2600
  White welding and dazzling                    2800


QUESTIONS FOR REVIEW

  What is meant by the carbon contents of steel? Why is steel graded
  according to its carbon content? Explain the cause of fire cracks.
  How can they be prevented? Why should steel be thoroughly healed? If
  steel is overheated or burned, what is the effect? Why should steel
  never be left in the fire to soak up heat? How does steel forge if
  it is unevenly heated? How should the blows be delivered in forging
  steel? What is annealing? Describe three methods of annealing. Is it
  best to anneal cold chisels and lathe tools? Explain the process of
  hardening steel. What effects does hardening have? Are the forging
  and the hardening heats the same? Why is steel polished after it
  is hardened? Explain the process of tempering. What is the effect
  of tempering? How may the heat be supplied for tempering? Name the
  colors in order as they appear in heating steel. Explain the methods
  of hardening and tempering. Why should a cold chisel be kept in
  motion when it is being hardened? What is meant by oil-tempering?
  What is meant by casehardening? Explain different methods of
  casehardening.



CHAPTER V

TOOL MAKING AND STOCK CALCULATION


=91. Tongs.=—As tongs are among the most important tools and quite
difficult to make, they will be taken up in this chapter on tool making.

The weakest places in a pair of tongs are where the shoulders or
offsets are formed for the jaws and handles. These places should be
reënforced by fillets as large as the usefulness and appearance of the
tongs will permit; they should never be made sharp and square, unless
their construction demands it.

All tongs for general blacksmithing can be forged properly with the
hand hammer and the use of such tools as the top fuller, the swages,
and the round-edged set hammer. Some assistance with a light sledge
will be necessary. The use of such tools as a square-edged set or the
file for forming shoulders or fillets is very objectionable, especially
in the hands of unskilled workmen. If the two parts do not seem to
fit as they should, due to the fillets which are present, they will
generally adjust themselves when they are riveted together, heated, and
worked freely.


=92. Heavy Flat Tongs.=—Fig. 74. Fullering, forging, swaging, punching,
and riveting. Material: 15 inches of 7/8-inch square mild steel.

Mark the center of the 15-inch length with a hardy or cold chisel.
Form two depressions 3/8 inch deep, with a top fuller, one 2 inches
from the end at _a_, the other 3 inches from the same end but on the
opposite side. Form a third depression to the same depth, but at an
angle of 45 degrees, starting from the bottom of the first one, and on
the side indicated by the broken line, as at _b_. Draw the 2-inch end
to 1 × 1/2 inch from _a_, tapering to 1 × 3/8 inch at the end. This
portion forms one jaw, as shown at _c_. Now flatten out about 2 inches
of the metal from the beveled depression _b_ toward the center mark,
to 9/16 inch thick, allowing the metal to spread as wide as possible.
This should then be forged and formed into shape for the joint _d_, and
the fuller again placed in the second depression to make the dimension
there 5/8 inch, as shown at _d_.

[Illustration: FIG. 74.—STEPS IN MAKING HEAVY FLAT TONGS.]

Forge the other end in the same manner, exerting due care to have all
dimensions correspond; cut the stock in two at the center. Draw out
the heavy ends for the handles with the power hammer or with some
assistance from a sledge. They should be roughly forged at first with
an allowance for finishing as follows: Beginning at the joint, use the
top and bottom swages on the outer edges through the greatest width,
and swage to 5/8 × 1/2 inch. This swaging should be continued toward
the end to form the handle. By using the flatter during the swaging,
the sides may be kept straight, smooth, and slightly tapering to a
round section. Make the end 3/8 inch in diameter for a length of 3
inches. Sketch _F_ shows one side of a pair of tongs drawn and swaged.

Place the parts together to see if they fit properly; if they do not,
make the necessary alterations. Use a top fuller to form a groove _e_
about 1/8 inch deep, lengthwise on the inside of the jaws, and smooth
the sides and edges with a flatter. Then punch a 3/8-inch hole in the
center of the joint, as shown in sketch _F_. This should be done on
both parts.

Heat thoroughly the end of a 3/8-inch rivet, 1-3/4 inches long, and
with it rivet the two portions tightly together. Heat the tongs, make
them work freely, and adjust them to hold 3/8-inch flat iron, with the
entire length of the jaws in contact and with the ends of the handles
1 inch apart. The jaws and handles should be adjusted so that a line
extended lengthwise across the center of the rivet would pass midway
between them.


=93. Light Chain Tongs.=—Fig. 75. Forging, swaging, punching,
fullering, and riveting. Material: 13 inches of 3/4-inch square mild
steel.

[Illustration: FIG. 75.—STEPS IN MAKING LIGHT CHAIN TONGS.]

Mark the center of this length with a hardy or cold chisel. Form a
shoulder 1-1/4 inches from the end, and draw this end to 7/8 × 1/2 inch
at the bottom of the shoulder, tapering to 3/4 × 3/8 inch at the end,
as at _a_. Form a second shoulder at an angle of 45 degrees, starting
from the bottom of the first one, by holding the work on the anvil, as
shown at _b_. The blows should be directed a little toward the center
mark, to flatten and spread the metal for forming the joint of the
tongs. Form a third shoulder at _c_, 1 inch from and on the opposite
side to the first and toward the center mark, the thickness here being
1/2 inch. Note that these shoulders should be made with overhanging
blows and not by using the fuller. The metal between the shoulders
_c_ and _a_ should now be forged into shape for the joint. Forge the
other end in a similar manner, being careful to have all dimensions
correspond; then cut the stock in two at the center.

Draw out the heavy ends for the handles with a power hammer or with
some assistance from a sledge. Roughly forge them from 1/2 × 7/16 at
_c_, down to 5/16 inch round, 3 inches from the end. Finish the edges
by using the top and bottom swages. By using the flatter on the sides
during the swaging, the handle may be kept straight, smooth, and
slightly tapered to where it terminates into round. Sketch _F_ in Fig.
74 shows the handle drawn out and swaged.

[Illustration: FIG. 76.—THE COMPLETED LIGHT TONGS.]

Place the two parts together to see if they fit properly; if they do
not, make the necessary alterations. Taking each piece separately,
perform the following operations: Fuller a groove 1/8 inch deep,
lengthwise on the inside of the jaw, and another crosswise about 1/4
inch from the end as shown at _A_, Fig. 76. Then punch a 5/16-inch hole
in the center of the joint. A 5/16-inch rivet 1-1/2 inches long should
be obtained, its end should be thoroughly heated, and the two parts
riveted tightly together. Heat the tongs and make them work freely;
adjust them to hold 3/16-inch flat iron with the full length of the
jaws in contact, also to hold 3/8-inch round material in the cross
groove when the handles are 1 inch apart. They should be adjusted,
so that if a line were extended lengthwise through the center of
the rivet, it would pass midway between the jaws and handles. When
complete these tongs will appear as in Fig. 76.


=94. Lathe Tools.=—A complete description of lathe tools would require
too much space in this book, therefore only six common ones will be
explained; by applying the knowledge received from making these, the
operator should be able to forge many others. These with the other
tool steel exercises should supply sufficient practice in forging,
hardening, and tempering tool steel.

If these tools are to be put into practical use, a good quality of
tool steel should be provided, cut about 8 inches long for each one,
and great care should be taken in the heating, forging, and tempering.
If, however, they are to be made for practice alone, then much shorter
pieces may be conveniently used, also an inferior grade of steel;
mild or soft steel would be sufficiently good to provide the needed
practice in heating, forging, and tempering. Even though the material
is inferior, the operations should receive the most careful attention.

The material may be 1 × 1/2-inch, 7/8 × 3/8-inch, or any suitable stock
size.

[Illustration: FIG. 77.—BRASS TOOL.]


=95. Brass Tool.=—Fig. 77. Forging, hardening, and tempering. Material:
6 to 8 inches of 1/2 × 1-inch tool steel.

Starting about 3/4 inch from one end, draw to a uniform taper on both
sides and on one edge only, so that the metal is 1/4 inch thick and 1/2
inch wide at the end. The lower or beveled edge also should be drawn
thinner than the upper to provide the necessary clearance amounting to
about 5 degrees on each side, as shown in the sectional view. The end
should be cut off at an angle of 70 degrees and ground semicircular in
form with the necessary clearance.

Heat about 2 inches of this end and harden in the manner described for
the cold chisel, but in this case the color for tempering is a very
pale yellow.


=96. Cutting-off or Parting Tool.=—Fig. 78. Fullering, forging,
hardening, and tempering. Material: 7 inches of 1/2 × 1-inch tool steel.

[Illustration: FIG. 78.—CUTTING-OFF OR PARTING TOOL.]

With a top fuller form a depression across one side 5/8 inch from the
end, fullering the metal to 3/16 inch thick. Draw this end down to 1 ×
3/16 inch. The thickness of the metal where it was fullered should also
be decreased to 1/8 inch, gradually increasing to 3/16 inch at the end,
taking extreme care to have sufficient clearance from front to back and
from top to bottom. The cutting edge is generally allowed to project
about 1/8 inch above the stock; the end is trimmed off at an angle of
75 to 80 degrees and ground, as shown in Fig. 78, after which it is
hardened and tempered to a pale yellow.


=97. Heavy Boring Tool.=—Fig. 79. Drawing, bending, hardening, and
tempering. Material: 7 inches of 1/2 × 1-inch tool steel.

[Illustration: FIG. 79.—HEAVY BORING TOOL.]

Draw about 2-1/2 inches tapering to 1/2 inch square at the end; the
taper on the top edge should be only 1/8 inch, while that on the bottom
should be 3/8 inch, as shown at _a_. With the metal resting flat on the
anvil and the top edge to the left, bend down 3/4 inch of the end to an
angle of about 80 degrees, then forge down the corners from the point
back to the heel, to a slight octagonal form, as shown in Fig. 79.
Grind the projecting end of the angle semicircular with a clearance of
15 degrees, then harden and temper to a pale yellow.


=98. Light Boring or Threading Tool.=—Fullering, drawing, hardening,
and tempering. Material: 5 inches of 1/2 × 1-inch tool steel.

Using a top fuller, form a depression 7/16 inch deep on one edge and
2 inches from the end. Draw this metal slightly tapering to 7/16 inch
square at the end, keeping it straight on the top. With the metal
resting flat on the anvil and the straight edge to the left, bend down
3/4 inch of the end to an angle of 80 degrees, then forge the corners
between the angle and where the depression was formed to a slight
octagonal form.

For a boring tool, grind the projecting end of the angle semicircular
in form, with sufficient clearance for boring a hole of the desired
size; for a threading tool grind it to the proper angle of the thread
with sufficient clearance, then harden and temper it to a pale yellow.


=99. Diamond Point Tool.=—Fig. 80. Forging, hardening, and tempering.
Material: 7 inches of 1/2 × 1-inch tool steel.

[Illustration: FIG. 80.—FIRST STEPS IN MAKING A DIAMOND POINT TOOL.]

Using a top fuller, form a depression 3/8 inch deep on one edge 3/4
inch from the end, as at _a_. Then holding the depression over a round
edge of the anvil and delivering blows on the end, as indicated at
_b_, forge the 3/4-inch end into a square form, at an angle of 70
degrees to the lower edge of the stock, as shown at _c_. By resting the
inner corners of this end on the face of the anvil and delivering blows
on the opposite outside corners, as shown in Fig. 81, its form should
be changed to 7/16 inch square, projecting diagonally from the stock,
as shown at _a_, Fig. 82.

[Illustration: FIG. 81.—CHANGING THE FORM OF _c_, FIG. 80, TO THAT OF
_a_, FIG. 82.]

[Illustration: FIG. 82.—DIAMOND POINT TOOL, FINISHED.]

By using a sharp, hot cutter and cutting entirely from the right inside
surface (_a_, Fig. 82), and by holding the point over the edge of the
anvil, so that the operation will have a shearing effect, the excess
metal which extends more than 3/8 inch above the upper line of the
stock may be removed. For a right-hand tool the point should be set
1/8 inch to the left, as shown at _b_, the two outside surfaces being
ground smooth and forming an acute angle; the inside portion of the
end on the side indicated by _a_ should be ground somewhat shorter,
producing a diamond-shaped appearance. Harden and temper to a very pale
yellow.

Reverse the operations of cutting, setting, and grinding for a
left-hand tool.


=100. Right Side Tool.=—Fig. 83. Forging, offsetting, hardening, and
tempering. Material: 7 inches of 1/2 × 1-inch tool steel.

[Illustration: FIG. 83.—FIRST STEPS IN MAKING THE SIDE TOOL.]

[Illustration: FIG. 84.—SIDE TOOL.]

Heat and cut off about 5/8 inch of one corner, as at _a_, Fig. 83, and
form a depression with the top fuller 1-1/2 inches from the end on
the side indicated at _b_, 1/4 inch deep at the upper edge, leaving
the metal full thickness at the lower edge. Then the metal should be
roughly spread out from the upper edge of the stock by holding the
fuller lengthwise, as shown at _C_, leaving the lower edge the full
thickness, and smoothed with a flatter, drawing the upper edge to
1/8 inch in thickness. The above operations could be done with a hand
hammer, but not without considerable hard work.

[Illustration: FIG. 85.—OFFSETTING THE SIDE TOOL FOR CLEARANCE.]

Trim this end to the form shown in Fig. 84, by using a sharp, hot
cutter and cutting entirely from the side indicated by _d_. When this
has been done correctly remove all metal extending more than 1/4 inch
above the upper edge of the stock. When this has been forged to the
correct shape, heat and place the tool so that the fullered shoulder
is just beyond the edge of the anvil, then form the offset with a
round-edged set hammer, as shown in Fig. 85. Grind the upper edge
parallel with the stock but at a slight angle, to produce a cutting
edge, and grind the face side straight and smooth. In cooling this tool
for hardening it should be placed in the water, as shown in Fig. 86,
to insure hardening the whole cutting edge. Leave sufficient heat in
the heel or bottom of the tool to draw the temper uniformly to a pale
yellow.

[Illustration: FIG. 86.—HARDENING THE SIDE TOOL.]


=101. Forging Tools.=—The following forging tools are somewhat
smaller than those used in general smith work, but they are perfectly
serviceable and sufficiently heavy for manual training or considerable
ordinary work. The material for their construction should be tool steel
of 0.80 to 0.90 per cent carbon, 1-1/4 inches square, unless otherwise
specified. The holes or eyes should be punched straight, and the
precautions formerly given under the head of punches should be observed.

A tapered drift pin of an oval section 7/8 × 5/8 inch at the largest
end, also a smaller oval-shaped handle punch, should first be provided.


=102. Cold Chisel.=—Fig. 87. Forging, hardening, and tempering tool
steel. Material: 6-1/2 inches of 3/4-inch octagonal tool steel.

[Illustration: FIG. 87.—COLD CHISEL.]

First draw 1/2 inch of one end to a smooth, round taper about 3/8 inch
in diameter at the extreme end, then grind off the rough projecting
edges until it is 1/2 inch in diameter. This end should not be cooled
quickly, because it might harden somewhat, which would cause it to
break easily. Starting 2 inches from the opposite end, draw the tool
tapering to 1/8 inch thick and 1 inch wide, using the flatter on these
tapered sides and edges. They should be made straight and smooth, with
the edges perfectly parallel. Two views with dimensions are shown in
Fig. 87.

Grind the cutting edge of the chisel to the desired angle, then harden
and temper it as follows: Heat about 2 inches of the cutting end to a
dull cherry red and plunge about 1 inch of this perpendicularly into
water; withdraw it about 1/2 inch, and keep it in motion between the
first and second cooling places until the end is perfectly cold. Remove
the tool and quickly polish one side with emery cloth or sandstone,
watching the varying colors as they make their appearance and move
toward the edge; when the dark purple or blue color entirely covers
the point, thrust it into the water again and leave it there until
thoroughly cooled. Regrind cautiously, protecting the temper, and test
its cutting qualities on a piece of cast iron or soft steel.


=103. Hot Cutter.=—Figs. 88 and 89. Punching, fullering, forging,
hardening, and tempering. Material: 4 inches of 1-1/4-inch square tool
steel.

[Illustration: FIG. 88.—STEPS IN MAKING THE HOT CUTTER.]

[Illustration: FIG. 89.—HOT CUTTER.]

Punch and drift an eyehole 1-3/4 inches from the end, making all sides
straight and smooth, as shown at _a_, Fig. 88. With a pair of 3/4-inch
fullers, form two depressions on opposite sides 1/4 inch from the eye,
as at _b_, fullering the metal to 5/8 inch thick. From this place draw
the end tapering to 1-1/2 × 1/8 inch, and trim it off at a right angle
to the stock, as at _c_. Using a hot cutter and working equally from
all sides, cut the tool from the bar 1-1/4 inches from the edge of the
eye. Draw the head end tapering to about 7/8 inch from the eye, draw
the corners to form a slightly octagonal section. Remove all projecting
metal so as to produce a convex head. (See Fig. 89.) This will be
referred to later as forming the head. Grind both sides of the cutting
end equally to form an angle of 60 degrees, with the cutting edge
parallel to the eye. Harden, and temper to a dark purple or blue.


=104. Cold Cutter.=—Figs. 90 and 91. Punching, forging, hardening, and
tempering. Material: 4 inches of 1-1/4-inch square tool steel.

[Illustration: FIG. 90.—STEPS IN MAKING THE COLD CUTTER.]

[Illustration: FIG. 91.—COLD CUTTER.]

Punch and drift an eye 2 inches from the end _a_, Fig. 90. Draw this
end tapering on the sides parallel with the eye, forming convex
surfaces and terminating in 1 × 3/16 inch. (See sketches _b_ and _c_.)
Cut the tool off at _c_, 1-1/4 inches from the eye, and form the head.

Grind the cutting end equally from both sides to form an angle of
60 degrees, and a convex cutting edge similar to that shown at _d_.
Harden, and temper to a dark purple or light blue. The finished tool is
shown in Fig. 91.

[Illustration: FIG. 92.—SQUARE-EDGED SET HAMMER.]


=105. Square-edged Set.=—Fig. 92. Punching and forging. Material: 3-1/2
inches of 1-inch square tool steel. Heavier or lighter stock may be
used if desired.

Punch and drift an eye 1-1/4 inches from the end, then, using a pair
of 3/8-inch fullers, form depressions about 1/8 inch deep across the
corners, as at _a_, Fig. 92. Cut the tool off 1-1/2 inches from the
eye, and form the head to 3/4 inch at the end. Heat and anneal in warm
ashes; when it is cold, grind the face smooth, straight, and at right
angles to the stock.


=106. Hardy.=—Fig. 93. Fullering, forging, hardening, and tempering.
Material: 3 inches of 2 × 7/8-inch tool steel.

Using steel 2 inches wide with a thickness equal to the dimension of
the hardy hole, fuller and draw a slightly tapered shank 1-3/4 or 2
inches long, to fit loosely into the anvil. The broken lines at _a_,
Fig. 93, indicate the drawn shank. Cut off the stock 1-1/2 inches from
the shoulders at _b_. Heat and drive the drawn end into the hardy hole
so as to square up the shoulders and fit them to the anvil. Then draw
the heavy end tapering gradually from the sides, terminating 1/8 inch
thick and 2 inches wide. Grind this tool similar to the hot cutter;
harden, and temper to a purple or blue.

[Illustration: FIG. 93.—HARDY.]

[Illustration: FIG. 94.—FLATTER OR ROUND-EDGED SET HAMMER.]


=107. Flatter.=—Fig. 94. Upsetting, forging, and punching. Material:
4-3/4 inches of 1-1/2-inch square tool steel.

In forming the face of a flatter, the metal should be upset. This
may be accomplished by ramming, but when so done, excess metal is
formed just above the wide portion, causing considerable fullering
and forging. If a piece of steel 4-3/4 inches long and 1-1/2 inches
square is cut off, and one end is drawn slightly tapering, it may,
when heated, be placed in a square hole of the right size in the swage
block, with the drawn end supported on something solid, leaving 1-1/2
inches projecting. The hot steel can then be hammered down with a
couple of sledges, until the face is formed to 3/8 inch thick or about
2 inches square, as at _a_, Fig. 94.

Punch and drift an eyehole 1-1/4 inches from the face, then draw and
form the head. Anneal in warm ashes. When it is cold, the face should
be ground perfectly straight, smooth, and at a right angle to the body,
with the surrounding edges slightly round, as shown, or they may be
left sharp and square if desired.

A round-edged set hammer may be made in this manner, but as the face
should not be so large, less metal is required.


=108. Small Crowbar.=—Fig. 95. Drawing, swaging, welding, and tempering
steel. Material: 16 inches of 3/4-inch square mild steel, also a small
piece of tool steel.

[Illustration: FIG. 95.—STEEL-FACED CROWBAR.]

Draw 11 inches to the following dimensions: the first 4 inches to
3/4-inch octagon, then beginning with 3/4-inch round gradually reduce
to 1/2-inch round at the end. This should be smoothly forged and swaged.

Form a depression 1/4 inch deep on one side of the square portion 2
inches from the end; from this, draw the metal to 1/2 × 3/4 inch; by
using a hot cutter where the depression was made, split and raise up a
scarf fully 3/4 inch long, as shown in the sketch. Prepare a piece of
tool steel 2-1/2 × 3/4 × 1/2 inches; on one end of this draw a long,
thin scarf and roughen it with a hot cutter, so it can be held in
place securely. (See Fig. 95.)

Heat the bar cautiously where the scarf was raised, to avoid burning
it; slightly cool the tool steel and put it into place. By holding
the piece of steel against a hardy, swage, or fuller, the scarf can
be hammered down tightly over the tool steel, which should hold it
securely for heating. Place the pieces in the fire and heat them to
a red; remove and thoroughly cover them with borax; replace them and
raise the heat to a bright yellow or welding heat.

While the first light blows for the welding are being delivered, the
end should be held against something to prevent the steel from being
displaced; when positive that welding is proceeding, make the blows
heavier and complete the operation.

When the pieces are securely joined, cut off the corner opposite to
the steel face, and draw the bar tapering from this side, to a sharp,
flat edge 1 inch wide. Bend this through its smallest dimensions to an
inside radius of about 3-1/2 or 4 inches and with the edge extending
1/2 inch to one side of the bar, as in Fig. 95. File or grind the
outside surface and edge of this; then harden, and temper to a blue.


=109. Eye or Ring Bolts.=—An assortment of eyes is shown in Figs. 96,
97, and 98. All eyes should possess two essentials: the necessary
strength and a good appearance; therefore the method of making should
be chosen to fulfill those requirements. Generally the eyes that have
the most strength require the greatest amount of labor.

_A_, Fig. 96, is an open eye which is very easily made, because bending
is the only operation required. The method of making this form of eye
has already been explained in section 69.

[Illustration: FIG. 96.—EYE OR RING BOLTS.

_A_, an open eye; _B_, a welded eye.]

_B_ is a welded eye. It is made by forming first a flat, pointed scarf
on the end of the bar and bending it through its smallest diameter
where the drawing was begun. This bend should be no less than 70
degrees on the outer side. Determine the length of the material needed
for forming a ring of the required diameter, then subtract the diameter
of the material from the determined length. Using this result, place a
center-punch mark _f_ that distance from _e_, and bend the piece at _f_
in the same direction as _e_.

Form the metal between the bends into a circle, and place the scarf in
position for welding, as at _B_. During the heating for welding, if the
circle heats more rapidly than desired, it should be cooled off and
the heating then continued. The welding should be done as quickly as
possible and swaged if required.

The eye bolt, shown in Fig. 97, is similar to a solid forged eye. It
is formed and welded with a specially forged scarf called a butterfly
scarf.

Determine the amount of material needed to form a ring of the required
diameter, and add to that a sufficient allowance for upsetting and
welding, which would be approximately equal to the diameter of the
material used. An invariable rule for that allowance cannot be given,
because the results of the upsetting are seldom the same.

Place a center-punch mark the estimated distance from one end of the
bar; then upset the end 1/8 inch larger than its original diameter,
next upset it at the mark to a similar dimension, and bend it there to
an angle of no less than 70 degrees. Now with the bend lying flat on
the face of the anvil, draw out a thin, narrow scarf with a small ball
peen hammer, not any wider than the thickness of the metal. The scarf
may be drawn also by holding the outer portion of the bend on a sharp
corner of the anvil and by drawing with overhanging blows. This scarf
is shown in the upper view of Fig. 97 as it should appear.

[Illustration: FIG. 97.—EYE BOLT MADE WITH A BUTTERFLY SCARF.]

The butterfly scarf should now be formed on the opposite side from
the one just finished, by holding each side of the end at an angle of
about 45 degrees on the edge of the anvil; this scarf may be drawn
with overhanging blows. The extreme end should also be drawn thin in a
similar manner, while it is held at a right angle with the edge of the
anvil. All outer edges of this scarf should be thin and sharp.

Bend the metal into a circle and place the scarfs in position, as shown
at _C_, having all edges overlapping slightly and hammered down into
close contact. Heat the work for welding, observing the precaution
given in the explanation of the former eye. In welding, deliver the
first few blows uprightly on each side, then weld the edges of the
scarfs with the ball of the hammer. A few careful experiments with
these scarfs will show what is required, and with practice no more
labor will be needed than is required for the previous eye. The
finished product will be more substantial and presentable.

[Illustration: FIG 98.—_D_, A SHIP-SMITH EYE; _E_, A SOLID FORGED EYE.]

_D_, Fig. 98, is generally called a ship-smith eye, because it is
commonly used in ship work where strength is essential. Special swages,
convex lengthwise, are usually provided for shaping the concave curves
where they are formed and welded. The eye should be circular between
the places indicated by _f_ in sketch _D_, and the lines from _f_
to where it is welded should be as nearly straight as possible, to
increase the strength.

In estimating the material, take two thirds of the length for a ring
of the required diameter, and add to that the proper allowance for the
stock which forms the portion from _f_ to the weld, and also an amount
sufficient for the scarf. This scarf is drawn similar to the one for
the welded eye in Fig. 96, but it should be made convex through its
smallest dimension with a top fuller, whose diameter is equal to that
of the metal. This is done while the metal is held in a bottom swage of
corresponding size. When the scarf is finished, bend the eye into shape
and bring the scarf close up to the stem of the eye.

Heat and weld with swages; if convex swages are not obtainable, others
may be used by taking care to prevent marring the curves. This eye may
also be welded with a large fuller while it is held over the horn of
the anvil. If the curves are severely marred, the strength of the eye
is lessened.

A solid forged eye is shown at _E_. When eyes like this are drop-forged
in special dies, as they generally are, they do not require much skill,
but when made entirely by hand they require considerable experience.

In forging an eye of this kind, the volume of material needed must
first be determined, making some extra allowance for the usual waste.
A convenient size of material should then be selected (round is
preferable) and the amount required for the eye marked off. The round
stem should be drawn down to size and the part for the eye forged to
a spherical shape, then flattened, punched, and enlarged to correct
dimensions.


=110. Calipers.=—The calipers shown in Fig. 99 may be easily made from
the dimensions given; 3/4 × 1/8-inch stock should be used for the main
piece, and 1/2 × 1/8-inch stock for the legs.


=111. Stock Calculation for Bending.=—In the expansion and contraction
of metals during the operation of bending, there is a fixed line,
where the metal is left undisturbed; in other words, where it is
not increased or decreased in length. So all measurements taken to
determine the length of material required for producing any bent shapes
should be taken from that fixed or undisturbed location, in order to
attain accurate results.

All materials which have a symmetrical cross section, such as round,
square, octagonal, oval, or oblong, have the above line at their true
centers, no matter which way they are bent. While the metal remains
undisturbed at the center of any of the above sections, the rest of
it undergoes a change; the inner portion, in the direction of bending,
will contract and become thicker, and the outer portion will expand and
become thinner.

[Illustration: FIG. 99.—STEPS IN MAKING CALIPERS.]

Other conditions arise, however, to modify these rules. If the heat is
unevenly distributed, or if the stock is not of a uniform thickness,
the results will not be exactly as estimated. When a heavy ring is
formed of oblong material and bent through its larger diameter, as
shown in sketch _A_, Fig. 100, and the product is to be finished to
a uniform thickness, the expansion of the outer portion will make it
necessary to use somewhat thicker material, to provide for the decrease
of metal which will take place. The inner half, then too thick, could
be reduced to the required size, but this operation always alters
natural conditions of bending, and changes the general results. These
conditions are not very noticeable and do not require special attention
when small-sized materials are operated upon, but they must be observed
when large oblong or square stock is formed into a ring requiring exact
dimensions.

[Illustration: FIG. 100.—CALCULATIONS OF LENGTHS FOR RINGS.]

In all cases of this kind, the required length must be established from
the undisturbed center and the ends cut at an angle of 85 degrees. If
the material is to be welded, it should be scarfed on opposite sides
and lapped when bent.

When hoops or bands of flat or oblong material are bent, scarfed, and
welded through the small diameter, then both scarfs should be formed on
the same side while straight, and bent as shown at _B_, Fig. 100; the
scarfs then will fit more readily than if they were formed on opposite
sides. Sometimes, in instances of this kind, only one end is scarfed,
and the piece is bent in a similar manner, with the unscarfed end on
the outside and just lapping enough to cover the heel of the inner
scarf.

Another form of ring requiring a calculation of the area as well as
of the length is one of a wedge-shaped section, as shown at _C_, Fig.
100. Here the area of the required section is found and the material
supplied with the proper thickness and area. The length also must be
computed, then cut, scarfed, and welded, as previously explained; after
this the ring may be drawn to the form desired.

The circumference of a circle may be found by multiplying its diameter
by 3.1416 (π). (See tables, pages 205-206.) For rings or bands the
length of the center line, _c_, Fig. 100, should be found. Example: If
_a_ equals 5 inches and _b_ equals 2 inches, _c_ will equal 7 inches,
and the length of stock for the ring will be 7 × 3.1416 = 21.991
inches,—practically 22 inches. 3-1/7 may be used for the value of π
instead of 3.1416.


QUESTIONS FOR REVIEW

  Describe the proper construction of a pair of tongs. What sort of
  steel should be used in making lathe tools? What operations are
  employed in making them? What is the color of the temper? If they
  were tempered to a blue, would they be tempered harder or softer?
  Are forging and hardening heats the same? State the difference in
  grinding a boring and a threading tool. Explain the difference in
  making a right- and a left-hand diamond point tool. How should a side
  tool be hardened? Why shouldn’t the head of a cold chisel be cooled
  off quickly when it is finished? Explain the difference between
  tempering a cold chisel and tempering a lathe tool. Describe the
  shapes of the hot and the cold cutter. How should they be tempered?
  How are the square-edged set and the flatter treated in place of
  tempering. Explain how it is done. Describe different methods of
  making eye or ring bolts. How should measurements be made on stock
  to be bent? State what has been said about scarfing flat or oblong
  material for rings.



CHAPTER VI

STEAM HAMMER, TOOLS, AND EXERCISES


=112. A Forging.=—A forging is an article made of metal, generally
steel or iron, and produced by heating and hammering. It may be used
for either practical or ornamental purposes. The various forgings
already described were made by methods such as the older class of
smiths practiced, and are called hand forgings. From a practical
standpoint these smiths were familiar with the characteristic
composition of metals and with the knowledge of how they should be
worked.

Many forgings are produced at present by machinery. The product is
satisfactory for most practical purposes, and is generally equal to
that made by hand. The machines used are the drop hammers, horizontal
and vertical presses, steam hammers, and numerous other devices. The
power used for operating them may be either steam, air, water, or
electricity.


=113. The Drop Hammer.=—The drop hammer is provided with a pair of dies
made of cast steel, one upper and one lower, having suitably shaped
depressions made in them for forming the forgings. The lower die is
held stationary on a solid foundation block, and the upper one is
secured to a heavy weight or hammer. This is raised perpendicularly and
allowed to drop upon the metal, which is held on the fixed die by the
smith, thus forming the forging.

If the work is small and simple, all depressions may be made in a
single pair of dies, and the forging can be completed with one hammer
and without changing the dies. Work somewhat complicated may require
two or more pairs of dies, with various shapes of depressions. The
stock is broken down or blocked out by the first pair and then
completed by the stamping and finishing dies. Larger pieces may require
also a number of pairs of dies, then an equal number of hammers may
be used, each fitted with a set of dies. The material is passed from
one to the other, and the work completed without changing dies, and
possibly without reheating the metal.


=114. Presses.=—Presses may be either horizontal or vertical and are
generally used for bending or pressing the metal into some desired
shape or form; they are quite convenient for producing duplicate and
accurate shapes. Forming-dies or blocks are also required here, but
they are generally made of cast iron, and their construction need not
be so accurate. After the presses have been properly adjusted, very
little skill is required in their operation,—simply the heating of the
material and placing it against a gauge or between the dies. One thrust
of the plunger will complete the operation.


=115. The Steam Hammer.=—The steam hammer was first recorded by Mr.
James Nasmyth in his “scheme book” on the 24th of November, 1839.
Although this was the exact date of its origin, he first saw it put
into practical use by the Creuzot Iron Works of France in 1842.
Nasmyth’s invention legally dates from June, 1842, when his patent was
procured.

Of the various machines that have been devised for the smith’s use, to
relieve him of the laboriousness of pounding metal into shape, there is
none that could take the place of this invention. Numerous shapes and
forms can be produced more accurately and rapidly by the employment of
the steam hammer than by the use of hand methods.

[Illustration: FIG. 101.—A STEAM HAMMER EQUIPPED WITH A FOOT LEVER.]

Before proceeding any further, a few words of warning and advice may
not be out of place. Although this invention is a great benefactor to
the smith, it is not possessed with human intelligence, nor is it a
respecter of persons. The power of steam will always exert its utmost
force when liberated, so do not let in too much steam at first. Unless
the material is held horizontally and flat on the die, the blow will
jar the hands badly and will bend the material. All tools such as
cutters and fullers should be held firmly but lightly, so that they may
adjust themselves to the die and the descending blow.

After the hammer has been put into motion, the blows will fall in a
perfectly routine manner. By his careful observation and a thorough
understanding of the necessary requirements, and by signals from the
smith, the hammer operator should regulate the force of the blows to
suit the smith’s convenience.

A caution pertaining to the tongs used for handling the material should
be carefully observed. Whenever work is to be forged with the steam
hammer, the material should be held with perfect-fitting tongs secured
by slipping a link over the handles; a few light blows delivered on the
link will tighten their grip.


=116. Steam Hammer Tools.=—First some necessary tools will be
explained, then exercises requiring their use will be given, followed
by a few operations where simple appliances are needed.

[Illustration: FIG. 102.—THE HACK OR CUTTER.]


=117. The hack or cutter= (Fig. 102) is used for nearly the same
purposes as the hot cutter already described. It should be made of
tool steel from 0.80 to 0.90 per cent carbon. The head or top is made
convex, as shown, and not more than 5/8 inch thick, tapering equally on
both sides to the cutting edge, which may be made either 3/16 or 1/4
inch thick. It should be ground straight and parallel to the top and
tempered to a dark blue.

The blade is about 2-1/4 or 2-1/2 inches wide, unless intended for
heavy forgings, when all dimensions should be increased. The width
of the blade should not be too great, however, for the broader the
cutter, the greater its liability to glance sidewise or turn over when
the blows are delivered upon it. The length of this cutter may be from
3-3/4 to 4 inches.

The handle may be about 28 inches long, approximately 3/4 inch in
diameter at _a_ and gradually tapered towards the end, where it is
about 1/2 inch. The portion indicated at _b_ is flattened to an oblong
section, as shown, to allow springing when the blows are delivered and
to prevent bruising the hands.


=118. The circular cutter= (Fig. 103) is made of the same material and
with a handle of similar dimensions and form as the hack. A section of
the cutting portion on _a-a_ is shown, and suitable dimensions given.
If convex ends are to be cut, the perpendicular side of the blade
should always be on the inner side of the curve, but on the outer side
for concave ends.

[Illustration: FIG. 103.—THE CIRCULAR CUTTER.]

An assortment of these cutters with various-sized arcs may be provided
to suit requirements, but quite frequently the curved cutting portion
is altered to suit the particular work at hand.

[Illustration: FIG. 104.—THE TRIMMING CHISEL.]


=119. The trimming chisel= (Fig. 104) is made quite similar to an
ordinary hot cutter and likewise provided with a wooden handle. It
should be strongly constructed, perfectly straight on one side, and not
too long from the cutting edge to the top to avoid its being turned
over when the blows are delivered upon it. The grinding should be done
on the tapered side only, with the cutting edge tempered to a dark blue.


=120. The cold cutter= (Fig. 105) is used for purposes similar to those
of the ordinary cold cutter. It should be strongly made in a triangular
form, as shown in the end view, also with a spring handle like that of
the hack. The top is made convex, and the sides taper to the cutting
edge, which should be ground equally from both sides. It should be
carefully tempered for cutting cold material.

[Illustration: FIG. 105.—THE COLD CUTTER.]

[Illustration: FIG. 106.—BREAKING COLD STOCK.]

In cutting stock with this tool, the material should be nicked
sufficiently deep on the exterior to allow it to be broken. By holding
the piece securely with the hammer, and the nicked portion even with
the edge of the dies, it may be broken off by a few blows from a
sledge. The steam hammer may also be used to break the stock when
nicked with the cold cutter. The piece should be placed on the lower
die of the hammer, as shown in Fig. 106, and broken by one or two sharp
blows from the hammer. A piece of round stock can be used instead of
the triangular piece of steel, with the same result. When material is
being broken in this way, see that no one is standing in a direct line
with the stock, as there is some liability of one or both pieces flying
in either direction.

[Illustration: FIG. 107.—CUTTING STOCK.]

When using the hack (Fig. 102) for cutting square stock, cut equally
from all sides, as shown at _a_, Fig. 107. This will produce smoother
ends than if it were cut unequally and will prevent the short end from
turning upward when the final blows are delivered. The fin or core
that is formed by the hack, shown at _b_, generally adheres to one of
the pieces, but it can be removed by using the trimming chisel in the
manner shown. These fins are commonly removed by the use of an ordinary
hot cutter and sledge.

The hack, if held perpendicularly, will not cut the end of either piece
square. If one end is to be cut square, the cutter should be held as
shown at _c_. Round material may be cut similarly, but to avoid marring
its circular section it may be held in a swage fitted to the hammer die.

Flat stock may be cut equally from both sides, or if it is cut nearly
through from one side, the operation can be completed by placing a
small piece of square untempered steel over the cut, as shown at _e_. A
sharp blow of the hammer will drive the steel through into the opening
and produce a straight, smooth cut.

When a semicircular end is to be produced, similar to that indicated by
the broken line at _d_, the circular cutter should be used. Here, also,
the cutting should be done equally from each side.

[Illustration: FIG. 108.—THE CHECKING TOOL OR SIDE FULLER.]


=121. The checking tool or side fuller= (Fig. 108) is made of tool
steel with a carbon content, the same as for the cutters. The handle
also is the same, with the exception of part _a_, which provides the
spring. Here, on account of its being used in two different positions,
a twisted form is much better, because the tool may spring in either
direction. From the end view you will notice that it has a triangular
section with one square corner and two curved ones.

A convenient dimension for this tool is about 2-1/2 inches over all
from the square to the circular corners. It would be convenient to have
a smaller one also, of about 1-1/2 inches. The length of this tool
should correspond with that of the cutters.

In use, one of the circular corners of the checking tool is forced into
the metal, forming a triangular-shaped depression, as shown at _b_. Two
depressions are shown in this sketch in opposite directions to each
other, made by holding the tool in different positions and using both
the circular edges. The object of this operation is to set off the
rectangular portion _b_ so that the ends _c-c_ can be drawn out without
disturbing the center.

[Illustration: FIG. 109.—THE FULLER.]


=122. The fuller= (Fig. 109) is made with a handle like that of the
checking tool, but the portion used for fullering is made circular
in section and about 4 inches long. An assortment of sizes should be
provided, with diameters of 1, 1-1/2, and 2 inches. When smaller sizes
are needed, a bar of round steel may be conveniently substituted. These
tools may be properly termed top fullers, because they are generally
held on top of the metal and the blows are delivered from above, thus
forming depressions on one side only. Sometimes double depressions are
required directly opposite to each other. In such cases a short piece
of round metal, the same size as the fuller, is placed on the die
directly under the top fuller, with the metal between the two.

If the depressions are to be only semicircular, a short piece of
half-round material may be provided which is not liable to be
dislocated or jarred out of position on the die.

[Illustration: FIG. 110.—THE SPRING FULLERS.]


=123. The combined spring fullers= (Fig. 110) are very convenient for
making double depressions. They are similar to the single fuller,
but are flattened out at _a_ and _b_, so that they may be opened for
various sizes of stock.

[Illustration: FIG. 111.—THE COMBINATION FULLER AND SET.]


=124. The combination fuller and set= (Fig. 111) may be made with a
straight, round handle, but a twisted one is more desirable, because
the tool is frequently used in different positions. It should be made
of a quality of steel that will withstand severe hammering without
becoming battered. The heavy end which forms the tool is made about
1-1/2 by 2-1/2 inches; the corners on one side are left sharp and
square, while those opposite are made quarter-round. One side of this
tool may be made almost semicircular if it is intended to be used as a
fuller. The length may be about 4 inches.

[Illustration: FIG. 112.—DRAWING AND FINISHING WITH THE COMBINATION
FULLER AND SET.]

This tool is used as a fuller or set in drawing metal between
projections which have been formed by using the checking tool. In Fig.
112 the sections of metal, indicated by _a_ and _c_, are to be drawn
to smaller dimensions. This cannot be done with the hammer, because
these places are narrower than the width of the hammer dies. At _c_ the
fuller or set is being used flatwise, which is the better way, because
the two round corners will not cause galling. At _a_ it is shown in use
edgewise; but this should not be continued after the opening has been
enlarged sufficiently to use the tool as at _c_, unless perfectly sharp
corners are desired.

Another convenient use for this tool is for finishing a roughly drawn
tapered piece of metal, as at _d_. Here are shown the roughened tapered
surfaces, as they have been produced by the hammer, also the method of
using the set. If there is much of this kind of work to be done, it
would be advisable to provide a special tool with a circular side which
could be used solely as a flatter.

[Illustration: FIG. 113.—THE COMBINED TOP AND BOTTOM SWAGES.]


=125. The combined top and bottom swages= (Fig. 113) are also called
spring swages, because they are somewhat flexible at the connecting
loop, which keeps them in adjustment. The best material for these
swages, on account of the constant hammering to which they are
subjected, is a good quality of mild or soft steel. Much hammering has
a tendency to crystallize the metal and causes frequent breakage.

The heavy parts forming the swages ought to be well proportioned and
made from sufficiently heavy stock. The handles are drawn out from the
same material and welded, or merely stub ends may be drawn from this
material, and then flat stock welded on to form the handles. In either
case the edges should be swaged half-round previous to welding. The top
and bottom of the handles are not parallel with the upper and lower
parts of the swages, because the heavy parts only should receive hammer
blows.

The grooves should be perfect semicircles, with the exception of the
edges indicated at _e_, which should be slightly round, as shown. This
prevents metal from becoming lodged in the swages. If the metal sticks,
the smith will be unable to revolve it in the swages, and it will
become oblong in section. The corners on top of the upper swage should
be removed, as shown, so that the blows will be received more directly
through its center.

[Illustration: FIG. 114.—THE TOP AND BOTTOM SWAGES.]


=126. The top and bottom swages= (_A_ and _B_, Fig. 114) are made
separate, but of the same quality of material as those just described.
The handle of the top swage _A_, however, should be round, with a small
portion flattened, as shown. The bottom swage _B_ is constructed with
projecting lugs _d_, as shown. The distance between the lugs should be
equal to the width of the lower hammer die, over which the swage should
fit closely enough to prevent its displacement. The swages may be used
together or separately, as desired, the lower one being convenient for
cutting round material, as it prevents marring the sectional form of
the stock.

[Illustration: FIG. 115.—THE BEVEL OR TAPER TOOL.]


=127. The bevel or taper tool= (Fig. 115) is provided with lugs and
fits the hammer die. When constructed for general use, the pitch should
not be too great, because it may be increased by placing a short piece
of metal under one end, as shown, or decreased by inserting metal under
the opposite end. The heavy end should be made as nearly perpendicular
as possible, with the outer edge of the die. This tool is very handy
for drawing any tapering work, such as cold chisels, levers, keys, etc.


=128. The V block= (Fig. 116) was introduced by the inventor of the
steam hammer, and was used instead of a bottom swage. When large, round
sections are to be produced, and swages of the proper size are not
obtainable, this tool may be used.

[Illustration: FIG. 116.—THE V BLOCK.]

When round stock is drawn without a swage, only two portions directly
opposite to each other are acted on by the hammer, thus causing some
liability of producing an oblong section or a hollow centered forging.
These difficulties are avoided to a certain extent by the use of the V
block, because the force of the blow acts in three directions.


=129. The yoke or saddle= (Fig. 117) should be made of heavy flat
material bent into the form of a U, with the ends perfectly straight
and parallel. It should be provided with lugs fitted to the lower die
so that both sides will stand erect and at right angles to it, as at
_A_. The distance between the sides may be of any convenient width,
2-1/2 inches or more, depending upon the character of the work to be
done. Semicircular depressions should be made on the edges, as shown at
_e_.

[Illustration: FIG. 117.—THE YOKE OR SADDLE.]

Another view of the yoke is given at _B_, with one side removed. As
seen here, it is used to draw weldless or solid rings after the stock
has been blocked out and a sufficiently large hole has been punched
in it to allow it to be hung over the pin _p_, which rests in the
depressions previously mentioned. Hammer blows can be delivered on the
exterior of the stock, thus drawing it and increasing its diameter. As
this is increased, larger pins should be used, to produce a smoother
and more evenly drawn ring.

The yoke, shown at _C_, is being used as a bridge for drawing the ends
of a solid forged jaw. By using it for purposes like this, considerable
hand labor may be saved.

[Illustration: FIG. 118.—_A_, BOLSTER; _B_, A PLUG PUNCH IN POSITION
FOR USE.]


=130. Bolsters or collars= (_a_, Fig. 118) are used for punching holes,
upsetting metal for bolt heads, and similar operations. They should be
made of soft steel.

=131. Punches.=—At _b_, Fig. 118, a plug punch is shown in position on
the metal over a washer or bolster ready for punching. When properly
located, a few blows of the hammer will force the punch through the
metal and produce a smoothly finished hole.

Notice that the punch is made somewhat tapering, and that the heavier
portion is driven through first. Precaution should be taken not to have
the punch fit the bolster too closely or be too long, also to have it
directly over the hole in the bolster before attempting to drive it
through.

Holes can be punched with ordinary handle punches, but care should be
taken not to have them too long; even then a bolster or something must
be used, so that the punch can be driven clear through the metal and
not come in contact with the lower hammer die.


=132. Steam Hammer Work.=—The following exercises are known as machine
forgings. They will require the use of the steam or power hammer and
the tools just described. It will be necessary to know beforehand
what parts of the work are to be finished, so as to provide a proper
allowance at those places. The term “finished” means that the surface
is to be removed by the machinist, and the work made smooth and to the
required dimensions.

All machine drawings should designate the parts that require finishing,
by either the entire word or just the letter “F.” The symbol is more
convenient to use for only certain parts, but if the entire forging is
to be finished, it may be indicated by “finished all over.”


=133. Crank Shaft.=—Fig. 119. This is shown without dimensions or
finish marks. Select stock sufficiently heavy to produce a forging
equal to that shown at _b_.

Make two depressions with the checking tool, as shown, the distance _c_
between them corresponding with the dimension _a_ on the crank. Draw
the ends square and straight on the lower side, as shown at _d_, then
octagonal, and then round. In this way the fillets and shoulders will
be equal, as shown at _e_. The two ends should be swaged smooth and
round, then made perfectly straight and at right angles to the crank.

[Illustration: FIG. 119.—STEPS IN MAKING A CRANK SHAFT.]


=134. Connecting Rod.=—Fig. 120. The volume of the material required
for section _e_ must first be estimated. Then ascertain how many inches
of the selected material will be required to give this volume. This
will be the distance _b_ for the fullering shown at _a_. The sizes of
the fullers to be used should be the same as the required radii _r_.
Fuller in the depressions as shown, so that they will correspond with
the dimensions _g_, _h_, and _l_ of the finished rod. The metal between
_g_ and _h_ should then be drawn slightly tapered, as shown in the top
view, and to a uniform thickness _l_. The small end must now be drawn
to the proper size and trimmed with the circular cutter. Make the rod
perfectly straight, with the ends parallel to each other and to the rod.

[Illustration: FIG. 120.—STEPS IN MAKING A CONNECTING ROD.]


=135. Rod Strap.=—Fig. 121. This forging is begun by blocking out, as
shown at _B_, with _e_ a little greater than _h_ and plenty of stock at
_f_. The length _k_ must equal _l_, with a slight allowance of surplus
metal for the bending operation.

Sketch _C_ shows the method of bending. A forming block _m_ should
be provided for this, the width of which corresponds nearly with the
dimension _g_, and the thickness is somewhat greater than that at _d_.
The length may be equal to the inside length of the finished strap, but
it could be used if shorter. By placing this block perpendicularly on
the bottom die, with the forging resting on it and a small piece of
metal _n_ for a blocking on top of that, the upper die may be brought
down and a full head of steam turned on while the stroke lever is held
down. Both ends can be bent down simultaneously with sledges.

[Illustration: FIG. 121.—STEPS IN MAKING A ROD STRAP.]

After the bending, there may be required more or less labor with the
flatter and sledge to square it up in proper shape. Then the ends can
be cut off to equal lengths with the hack or hot cutter.

[Illustration: FIG. 122.—STEPS IN MAKING AN ECCENTRIC JAW.]


=136. Eccentric Jaw.=—_A_, Fig. 122. First form the depression _c_ with
the checking tool; then draw out the end _d_ to the form _e_ and punch
a hole at _f_ by using an oblong punch.

Then using the hack, carefully cut from both sides at the places
indicated by the broken lines at _f_. Any fin remaining after the
cutting can be removed with a hot cutter or the trimming chisel. The
ends forming the jaw can be drawn to the proper size by the use of
the yoke. The semicircular ends can also be cut by using the circular
cutter, but these ends will require some trimming with a hot cutter,
because all the work must be done from exterior sides.


=137. Hand Lever.=—_A_, Fig. 123. This illustrates and explains a
simple method of stamping which may be extended or adjusted to suit a
variety of forgings.

[Illustration: FIG. 123.—STEPS IN MAKING A HAND LEVER.]

In this case two stamping rings are made to suit the work at hand, as
follows: If the dimension _h_ is 2 inches and the thickness of the
lever _i_ is 1/2 inch, the rings must be made of 3/4-inch round stock,
and welded to an inside diameter corresponding with the dimension _k_.

First draw the material to correspond exactly with the dimension _k_ in
one direction and somewhat greater than that of _h_ in the opposite.
The latter dimension is made larger, to provide some excess metal for
the stamping operation, which is done in the following manner: Place
one of the rings centrally on the bottom die of the hammer, as shown
at _B_; lay the material on this, with the dimension _h_ perpendicular
and the proper distance from the end to provide enough metal for
forming the lever and handle. Then place the other ring on top of the
material directly above the lower one, and deliver blows on these
rings until the entire thickness almost corresponds with the desired
dimension _h_. The rings will be forced into the metal and form two
depressions, as shown at _C_. Next with a hot cutter or trimming chisel
remove the metal forming the corners _e_. Then draw out the lever
portion roughly, at first; by using the taper tool a uniform taper can
be produced correctly. Cut off the extra stock at the boss, and remove
the surplus metal which projects between the bosses as indicated at
_d_, and finish the end smoothly with a common top swage. The handle
portion can be formed at the anvil with top and bottom swages after the
end has been cut semicircular and to the desired length.

[Illustration: FIG. 124.—STEPS IN MAKING A CONNECTING LEVER.]


=138. Connecting Lever.=—_A_, Fig. 124. After drawing the metal to an
appropriate dimension, fuller two depressions _b_ on opposite sides,
the proper distance from the end, to form the jaw. A single boss _c_
should be stamped with one ring, at the required distance from _b_
to provide the necessary amount of metal for the length _d_ of the
lever. Then remove the corners, as indicated by the broken lines. Begin
drawing the lever by using the combination set, and finish the flat
side with the hammer, producing the taper edge with the taper tool.
Punch a square hole in the jaw and remove the metal indicated by the
broken lines at _e_, with a hot cutter. Finish the jaw similar to the
eccentric jaw and the boss as in the previous exercise.

[Illustration: FIG. 125.—SOLID FORGED RING.]


=139. Solid Forged Ring.=—Fig. 125. This should be made of soft steel,
the dimensions being supplied by the instructor to suit the stock and
equipment at hand. The volume (see calculating rules and tables, pp.
197-206) of the forging must first be determined and some surplus
allowance for forging provided. The process of making the ring will be
found in the explanation of the use of the yoke in section 129.

[Illustration: FIG. 126.—PRODUCING DOUBLE AND SINGLE OFFSETS.]


=140. Double and Single Offsets.=—Fig. 126. The following exercises
are given to explain the use of simple appliances for producing work
accurately and rapidly. Examples similar to the four following ones
would require considerable care and skill if they were to be produced
without the use of the steam hammer.

At _a_ is shown a double offset bend, the depth of which, for
illustration, may be 1/2 inch. To produce this, place two pieces of
1/2-inch flat material, with _width corresponding_ to that of the
material to be bent, on the lower die, and sufficiently far apart
to allow the offsets to form between them. On these the material is
placed, and on top of that also, located midway between the 1/2-inch
supporting pieces, a third piece of 1/2-inch stock is placed. The
width of this should correspond with the required dimension at _a_ and
should be somewhat longer than the width of the material to be bent.
This arrangement is shown at _c_. By delivering a sufficiently heavy
blow upon them, the two offsets, will be formed simultaneously and
accurately.

[Illustration: FIG. 127.—SIMPLE METHODS FOR BENDING CLAMPS WITH A STEAM
HAMMER.]

In all operations of this kind the thickness of the lower forming
pieces should always correspond with the required depth of the offset,
and the corners should be ground round to prevent shearing or galling.

At _d_ is shown a single offset which can be produced in a similar way,
with the exception that here only two blocks are required. But the
forming corners of these should also be ground as previously stated,
and they are placed in position as shown at _e_.

Figure 127 shows the method of bending a semicircular pipe or rod
clamp. Here a piece of round stock _f_ is used above for stamping, but
as the lower blocks are easily displaced, it would be advisable to make
a stamping block like that shown at _g_. This could be used instead of
the two lower pieces. If the clamps were to be made square, then the
stamping block should be like the one shown at _h_, and the upper piece
as at _f_ should be made square.


QUESTIONS FOR REVIEW

  What is a forging? Name the machines used in making forgings. Who
  invented the steam hammer? How should material be held on the dies?
  What tool is used in place of a hot cutter at the hammer? How can
  a convex end be produced? Describe the special form of a trimming
  chisel. How should metal be broken after it has been nicked with the
  cold cutter? Describe the correct way of using a hack in cutting
  square stock. Explain the use of a checking tool. Describe the
  different fullers used at the hammer. Explain their uses. For what
  is a combination fuller and set used? Describe the hammer swages.
  The bevel or taper tool. What is it used for? What is the advantage
  in the use of the V block? Describe the yoke. Explain its use. What
  is the difference between a plug punch and a handle punch? How is a
  bolster used for punching? What does the word “finished” mean on a
  drawing? What hammer tools are brought into use in making a crank
  shaft? In making the connecting rod? Describe how the hammer is used
  in bending a rod strap. What tools are brought into use in making the
  eccentric jaw? Describe the method of forming the bosses on the hand
  lever. Explain some simple methods of bending work with the steam
  hammer.



CHAPTER VII

ART SMITHING AND SCROLL WORK


=141. Art Smithing.=—This subject might appropriately be considered a
separate branch, because many smiths, who really deserve the credit
of being excellent mechanics, have never become proficient in this
particular line of work.

Art smithing is the highest development of metal work. The best art
smiths are foreigners, as European countries use much more of this kind
of work for decoration than this country does. The greater part of this
work is entirely too difficult for the average student unless it is
attempted with the assistance of machinery.

It is possible, however, to do a certain amount of scroll work with
accuracy and make simple decorative pieces. One should commence with
the design of the article to be made. The harmonious combinations of
straight and curved lines and their adaptation for different purposes
should be studied. The study of design will not be taken up here, but
several examples which will furnish a basis for further work along this
line are given for consideration.

Designing may be done on any convenient material such as paper,
wood, or blackboard. The last is preferable because confusing marks
can easily be erased. A sketch thus made may be used as a working
drawing. If the design is to be used many times, a very convenient and
substantial method is to reproduce it on a piece of shellacked pine
board, and then paint it on in solid form. When this is dry, a few more
coats of shellac should be applied to preserve it. If desired, the
length of each individual scroll may be indicated.

There are various methods of obtaining the different lengths: by
placing a strong string over the scroll and then measuring the string;
by using a piece of soft wire in the same manner, lead wire being
preferred; or by the following method:—

Take a piece of 1/8-inch material 3 or 4 feet long, mark it lightly on
both edges into equal spaces either 3 or 6 inches long, and stamp the
feet or inches upon it with steel figures. After this is done, a small
rolling curl, as shown in Fig. 129, should be formed, and the entire
length bent on the scroll former while the material is cold. This is
the manner, minus the markings mentioned, in which all scrolls are to
be formed. This product with the markings upon it should be kept for
ascertaining the number of inches required for either large or small
scrolls. Always place the curled end of this measure in position on
the working drawing and adjust it until it conforms to the outline
of the design. Then place a crayon mark on both the drawing and the
measure where they cease to correspond; the length of that portion
which corresponds can be ascertained from the markings on the measure,
and all remaining irregular curves can be measured by a string, wire,
or rule. This measure will prove also to be quite a satisfactory and
accurate means of arranging new designs.


=142. Scroll Fastenings.=—There are three different methods used for
joining scrolls: welding, riveting, and banding with clips. The first
is the most difficult and the most artistic, but unless one is quite
expert at welding, especially in joining light material such as is
generally used for scroll work, it would perhaps be better to disregard
this method entirely.

Riveting presents a very neat appearance and makes the product quite
strong and substantial, but unless the marking and drilling of holes
is accurately done, the result presents a distorted and ill-shaped
combination, which cannot be remedied without drilling new holes.

It would be advisable, then, to adopt the last method generally,
resorting to riveting wherever it is impossible to use clips or bands,
or where strength is an essential requirement. If a clip is misplaced,
it can be replaced with a new one, or it may be moved into the proper
position without showing that an error has been made.

[Illustration: FIG. 128.—THE SCROLL FORMER.]


=143. Scroll Former.=—Fig. 128. This is a very handy tool for producing
scrolls in a rapid and uniform manner. It should be a perfectly
designed variable spiral. If several are provided, they should be
exactly alike, otherwise the scrolls produced with them will be unequal
and irregular and will present an inartistic appearance. The former
illustrated is made of 1 × 1/2-inch soft steel. Draw the end and form
the central portion, gradually tapering to about 3/16 of an inch thick,
but leave it of a uniform width. This end should be slightly beveled
from one side to form a protruding edge, over which the small curled
end of the material is securely held while the scroll is being bent. A
view of the former as it is used to start a scroll is given in Fig. 129
showing the metal in proper position for forming. The end indicated at
_a_, Fig. 128, may be bent downward and edgewise to a right angle, as
shown, or, if desired, it may be forged square to fit the hardy hole of
the anvil, but as this tool is most conveniently used when held in the
vise, the method shown at _a_ is better.

[Illustration: FIG. 129.—STARTING A SCROLL ON THE FORMER.]


=144. Bending or Twisting Fork.=—Fig. 130. This fork is shown with
dimensions suitable for bending material 1/8 or 3/16 inch in thickness.
For thicker material all dimensions should be proportionately increased.

[Illustration: FIG. 130.—BENDING OR TWISTING FORK.]

This tool is very serviceable and quite easily made of round tool
steel; if such stock is not at hand, octagonal tool steel can be
swaged to the desired dimension. If it is made of soft steel, it will
meet requirements for a considerable length of time.


=145. Bending or Twisting Wrench.=—Fig. 131. This should be made from
the same quality of steel of the same dimensions as the preceding tool.

[Illustration: FIG. 131.—BENDING OR TWISTING WRENCH.]

[Illustration: FIG. 132.—SCROLL BENDING.]

The bending wrench is used in connection with the bending fork for
shaping a scroll, as shown in Fig. 132. When the wrench is placed over
the material so that its jaws will grip the sides and the handle of the
wrench is pulled in the direction indicated by the arrow, bending will
take place at _e_. If the straight end of the scroll were pulled in the
same direction, bending would occur at _f_. Sometimes when scrolls are
being connected with the band, they are sprung out of place. By the use
of this wrench they can be brought again into position by bending them
close to where the band was put on.

These tools may be used together for twisting light material, when the
vise and monkey wrench could not readily be utilized.

[Illustration: FIG. 133.—CLIP FORMER.]


=146. Clip Former.=—Fig. 133. This and the two following tools should
be made of 0.80 to 0.90 per cent carbon tool steel. A convenient size
of material for the one shown is 1 × 1/2 inch. The portion forming the
connecting loop must be flattened and forged to about 1/4 inch thick to
provide a spring for retaining its shape. The ends should be forged to
two different thicknesses. The 1/4-inch side is used in bending clips
for banding two pieces of 1/8-inch material, and the 3/8-inch side for
three pieces. When a different thickness of material is to be used,
these ends should be made to correspond with it. The inner and outer
edges of these ends should be made slightly rounding to prevent cutting
the material from which the clips are made. Most of this light scroll
work is made from stock with round edges, therefore it is not necessary
to have the clips bent sharp and square.

[Illustration: FIG. 134.—USE OF THE CLIP FORMER.]

The former should be so proportioned that it can be placed between the
jaws of the vise, as shown in Fig. 134. Here the loop is resting on
the box of the vise, which supports it and prevents it from falling
out of position when the pressure of the vise is released. The ends
of the clip former should extend above the jaws of the vise about 2
inches, so that the clips can be bent without striking the vise with
the hammer. A view of these ends, with a piece of half-oval iron in
position for bending, is shown at _A_, Fig. 137. One end of the clip
material should be placed between the ends of the former, one half the
width of the scroll stock, 3/16 of an inch if the stock is 3/8 inch
wide. By tightening the jaws of the vise upon the sides of the former,
the half-oval iron will be securely held, while it is being bent over
with the hand hammer to the form indicated by the broken lines. The
clip will then be ready for fastening the scrolls together.

[Illustration: FIG. 135.—CLIP HOLDER.]

[Illustration: FIG. 136.—USE OF THE CLIP HOLDER.]


=147. Clip Holder.=—Fig. 135. Stock 3/4 inch square is best suited for
making this tool. The central portion forming the loop should be drawn
and forged to about 1/4 inch thick, gradually increased to 1/2 inch
where the shoulders are formed. The distance from these shoulders to
the outside end of the loop should be less than the distance from the
top of the vise jaws to the vise box. Then the tool will be supported
entirely on these shoulders, as shown in Fig. 136, and the tool may be
placed near the ends of the vise jaws, which sometimes will prove to
be quite an advantage. The length from the shoulders to the ends may
be about 2 inches. These ends should be drawn tapering from the outer
sides to about 1/2 inch square. On the inside a depression 3/16 inch
deep should be formed so that the holder will fit over the bent end of
a clip, as shown at _B_, Fig. 137.

[Illustration: FIG. 137.—FORMING A CLIP.]

The clip and a sectional view of the two pieces of material that are
to be connected are shown at _B_ as they are placed in this tool. By
tightening the vise upon the holder, the lower portion of the clip will
be clamped securely on the pieces and held while the upright end of the
clip is bent over and around the upper half of the material with the
hand hammer. Then the following tool will be brought into use.


=148. Clip Tightener or Clincher.=—Fig. 138. The most convenient stock
from which to make this tool is 3/4-inch octagon tool steel. It is
made by upsetting and forging the end to about 1-1/4 × 1/2 inches,
then filing a depression not more than 3/16 inch deep and wide enough
to fit tightly over the outer portion of the bent end of a clip. The
corners indicated at _e_ should be made slightly round to prevent them
from marring the outside of the clips. This tool should be about 6-1/2
inches long, with the head end drawn as for a cold chisel.

[Illustration: FIG. 138.—CLIP TIGHTENER OR CLINCHER.]

By holding this tool on top of the bent-over clip, as shown at _C_,
Fig. 137, and delivering a few heavy blows upon it, the clip will be
tightened and clinched securely over and around the pieces.

[Illustration: FIG. 139.—JARDINIÈRE STAND OR TABORET.]


=149. Jardinière Stand or Taboret.=—Fig. 139. The height from the floor
line to the top of the circular board is 26 inches; the height from
the floor line to the upper ring _E_ is 19-1/2 inches; the height from
the floor line to the lower ring _F_ is 7 inches; the extreme width is
18-1/2 inches.

The process of making this stand will be given here. By following a
similar course, any of the other designs given in this chapter may be
made. The material usually employed for making this is 1/2 × 1/8-inch,
and there should be four sections or legs, as shown at the left, also
two bands or rings, like the one shown in the upper right, and one
top board 7/8 inch thick and 8 inches in diameter, which is shown
under the ring. The following list gives the number and lengths of the
various pieces required:—

  4 pieces 45-1/2 inches long.
  4 pieces 22-1/2 inches long.
  4 pieces 15-1/2 inches long.
  4 pieces 15 inches long.
  2 pieces 14-1/2 inches long.
  4 pieces 13 inches long.

All pieces should be straightened immediately after being cut to
length. The main branch, 45-1/2 inches long, should be marked with a
center punch at all places where bending or twisting is to be done.
From the end of the stock to _A_ is 6 inches; from _A_ to _B_, 9
inches; _B_ to _C_, 4-1/2 inches; the length of the twisted portion is
2-1/2 inches.

All ends that are to be scrolled, should be drawn, curled, and fitted
to the central portion of the former, as previously indicated. When
_both_ ends of the same piece are to be scrolled, observe carefully
whether they revolve in the _same_ or in _opposite_ directions. These
ends should not be cooled after drawing and fitting, because cooling
will have a tendency to harden them slightly and prevent uniform
bending. All ends that are to be connected to another piece by clips
should now be drawn out to a thin edge, but of a uniform width.

Now proceed to form the main branch by making the twisted portion
between _B_ and _C_; straighten if necessary. Form the upper angular
bend of 90 degrees at _A_ while it is held in the vise; this can be
done cold, by carefully avoiding breaking or cutting the material with
the sharp edge of the vise. Now form a scroll at the top on the former.
Next bend at _B_ in the same manner and direction as before, and make
the two quarter circles between _A_ and _B_, with the bending fork
alone or by combining the use of it with the bending wrench. Exercise
care in doing this, in order to have the correct space for scroll 2
and ring _E_, which should be 5 inches outside diameter. The lower
angular bend at _C_ should now be made, followed by forming as much of
the scroll _D_ as possible on the former. Then bend the irregular curve
between _D_ and _C_.

The next member to be scrolled and fitted into position is the
15-1/2-inch piece, 4. This must be carefully made in order to have the
extreme height of the scroll at the proper distance from the bottom
line, also at the proper distance from the center line, to provide
an exact dimension where the lower ring _F_ is to be connected. The
outside diameter of ring _F_ should be 5 inches. Then scroll and fit
the 15-inch piece, 3, followed by the 13-inch piece, 5, and finish this
leg by arranging the 22-1/2-inch piece, 2, last, so that it will not
extend above the bottom line of the circular board and will leave at
least a 1/4-inch space between the center line and the sides of the
curves.

All parts should be assembled on the drawing after they are fitted, and
marked with crayon wherever the clips are to be placed to secure them.
The material for the clips, which should be 3/8-inch half-oval Norway
iron, should be cut up in lengths equal to the four outside dimensions
of the combined materials plus 1/8 of an inch for bending, or 1-5/8
inches in this case. After these pieces are bent on the clip former,
fasten the scrolls together with the clip holder and the clincher.

After the four legs or parts have been assembled, lay each separately
on the drawing, to make sure that the places, where they are to be
connected with the rings and the circular board, are properly located.
If they are correct, mark these places with a center punch, and drill
9/64-inch holes where the rings are to be connected and 3/16-inch holes
where the top is to be secured.

The two 14-1/2-inch pieces are for the rings. Drill a 9/64-inch hole
3/8 of an inch from each end in both pieces, countersink one side of
one end of each piece, and grind a beveled edge on this end, but on
the opposite side from the countersink. Form them into rings having
the countersink inside. Connect the ends of each ring with a 1/8 ×
3/8-inch round-head rivet, inserting it from the outside of the ring
and riveting the ends together, filling the countersink. Place the
rings separately on the mandrel and make them perfectly round on the
inside by forming a slight offset on the outside end where it begins to
lap over the beveled inside end.

Draw a 5-inch circle on a piece of board and divide it into quarters.
Place the rings on this outline with the outside end about 1/4 inch
from one of the quarter lines. Mark where each quarter line crosses the
ring, center-punch these places, drill 9/64-inch holes, and countersink
them on the inside. Then assemble the legs by riveting the upper ring
to the standard with 1/8 × 1/2-inch rivets, the lower one with 1/8 ×
3/8-inch rivets, their heads toward the exterior so that riveting will
be done on the inside of the rings filling the countersink. Place the
circular top board in position and secure it with 1-inch #10 round-head
wood screws. This will complete the construction, with the exception of
a coat of black japanning, if a glossy finish is desired, or a coat of
dead black lacquer if a rich dull black is desired.

[Illustration: FIG. 140.—UMBRELLA STAND.]


=150. Umbrella Stand.=—Fig. 140. Extreme height, 27-1/2 inches; extreme
width, 18-1/2 inches; upper rings, 9-1/4 inches inside diameter;
lower ring, 5-1/4 inches inside diameter. Provide a small deep pan to
rest on top of this ring.

[Illustration: FIG. 141.—READING LAMP.]


=151. Reading Lamp.=—Fig. 141. Extreme height, 23 inches; height of the
stand, 14 inches; base, 8-1/4 inches wide; shade, 14 × 14 inches wide,
6-1/4 inches high, top opening, 4 × 4 inches.

[Illustration: FIG. 142.—ANDIRONS AND BAR.]


=152. Andirons and Bar.=—Fig. 142. Extreme height, 24 inches; extreme
width of base, 18 inches; height from the floor line to the top of the
upper scroll, 11-1/2 inches; length of bar, 40 inches.

[Illustration: FIG. 143.—FIRE SET.]


=153. Fire Set.=—Fig. 143. Extreme height, 30 inches; height to the
holders, 24 inches; height to the top of the upper scroll, 11-1/2
inches; extreme width of the base, 14 inches.

[Illustration: FIG. 144.—FIRE SET SEPARATED.]


=154. Fire Set Separated.=—Fig. 144. Extreme length of implements, 22
inches.


QUESTIONS FOR REVIEW

  Explain three methods of obtaining the length of a scroll. Should
  scrolls be bent hot or cold? Why are the ends of the clip former
  made to different thicknesses? Why is the clip former made thinner
  at the loop? How is that tool placed in the vise? Why is the clip
  holder made with shoulders on its outer sides? Give the rule for
  cutting off clip stock. After the scroll material has been cut to
  length, what should be done? When ready to draw and bend the curl for
  a scroll what should be observed? Why shouldn’t it be cooled after
  drawing and curling? What is done with the ends of a scroll if they
  are to be fastened with clips? Explain how the rings are made for the
  jardinière stand. Describe the process of making the umbrella stand
  in Fig. 140.



CHAPTER VIII

IRON ORE, PREPARATION AND SMELTING


=155. Iron Ore.=—An ore is a portion of the earth’s substance
containing metal for which it is mined and worked; the class to
which it belongs depends upon the amount and variety of the metal it
contains. Any ore that is to be used for the extraction of a certain
metal must contain the metal in sufficient amounts to make the
operation profitable.

Iron, ordinarily, does not occur in a native state or in a condition
suitable for use in the arts and manufactures. The iron in meteors,
frequently called native iron, is the nearest possible approach to
it. Meteorites, commonly known as falling stones or shooting stars,
are solid masses that have fallen from high regions of the atmosphere
and are only occasionally found in different parts of the world. They
are considered more valuable as a curiosity than as material for
manufacturing purposes. The metallurgist, chemist, or geologist can
readily distinguish them from other masses, because they invariably
contain considerable nickel, which seldom appears in any of the
ordinary iron ores. They are usually found in a mass containing
crystals and are nearly always covered with a thin coating of oxide,
which protects the metal from further oxidation. Several large meteors
have been found, one in Germany weighing 3300 pounds and a larger
one in Greenland weighing 49,000 pounds. The largest one known was
discovered by Lieutenant Peary in the Arctic regions. It weighs 75,000
pounds. He brought it to New York City, where it can now be seen at the
American Museum of Natural History.

Pure iron is obtainable only as a chemical, and as such it is used in
the preparation of medicines. As a commercial product, such as is used
in the arts and manufactures and by the smith, it is always combined
with other substances, such as carbon, silicon, and phosphorus.

Iron is distributed through the earth very widely, but not always in
sufficient quantities to make its extraction from the ore profitable;
consequently the ores used for the extraction of iron are somewhat
limited. There are four general grades of iron ore, which are known by
the following names: magnetite, red hematite, limonite, and ferrous
carbonate. These are subdivided and classified according to the
particular composition of each.


=156. Magnetite= when pure contains about 72 per cent of iron, and so
is the richest ore used in the manufactures. It is black, brittle, and
generally magnetic, and leaves a black streak when drawn across a piece
of unglazed porcelain. It sometimes occurs in crystals or in a granular
condition like sand, but generally in a massive form. It is found
principally in a belt running along the eastern coast of the United
States, from Lake Champlain to South Carolina. There are considerable
quantities of it in New Jersey and eastern Pennsylvania, but the
greatest deposits are found in Missouri and northern Michigan; some is
mined also in eastern Canada. It is a valuable ore in Sweden.

A mineral known as franklinite, which is closely allied to magnetite,
is a mixture of magnetite and oxides of manganese and zinc. In
appearance it resembles magnetite, but is less magnetic. In New Jersey,
where it is found quite abundantly, it is treated for the extraction of
the zinc, and the residue thus obtained is used for the manufacture of
spiegeleisen, which is an iron containing a large amount of manganese,
usually from 8 to 25 per cent.


=157. Red hematite= is found in earthy and compact forms. It varies in
color from a deep red to a steel gray, but all varieties leave a red
streak on unglazed porcelain. It is found also in a number of shapes
or varieties, such as crystalline, columnar, fibrous, and masses of
irregular form. Special names have been given to these. The brilliant
crystalline variety is known as specular ore, the scaly foliated
kind as micaceous ore, and the earthy one as red ocher. Each one of
this class contains about 70 per cent of iron, and on account of the
abundance, the comparative freedom from injurious ingredients, and the
quality of iron it produces, it is considered the most important of all
the ores in the United States.

Until the discovery of large deposits of this ore in the Lake Superior
district it was chiefly obtained from a belt extending along the
eastern coast of the United States just west of the magnetite deposits
and ending in Alabama. Some of this ore is found in New York, but
there is not a great amount of it north of Danville, Pennsylvania.
At present the greatest quantities that are used come from the Lake
Superior district. There, ore of almost any desired composition may be
obtained, and the enormous quantities, the purity, the small cost of
mining, and the excellent shipping facilities have made it the greatest
ore-producing section of the United States.


=158. Limonite or brown hematite= contains about 60 per cent of iron
and is found in both compact and earthy varieties. Pipe or stalactitic
and bog ore belong to this grade. The color varies from brownish
black to yellowish brown, but they all leave a yellowish brown streak
on unglazed porcelain. It is found in a belt lying between the red
hematite and magnetite ores in the eastern United States. Formerly
there was considerable of this mined in central Pennsylvania, Alabama,
and the Lake Superior district.


=159. Ferrous carbonate= contains about 50 per cent of iron. It also
is found in several varieties, called spathic ore, clay ironstone, and
blackband. Spathic ore when quite pure has a pearly luster and varies
in color from yellow to brown. The crystallized variety is known as
siderite; this ore frequently contains considerable manganese and in
some places is used for the production of spiegeleisen. When siderite
is exposed to the action of the air and water, brown hematite is formed.

Clay ironstone is a variety that is found in rounded masses or
irregular shapes and sometimes in layers or lumps, usually in the
coal measures. It varies in color from light yellow to brown, but the
light-colored ore rapidly becomes brown when exposed to the atmosphere.
Like the former it also contains considerable manganese.

Blackband is also a clay ironstone, but it is so dark in color that
it frequently resembles coal; hence the name. The ore is not very
abundant in this country nor extensively used; it is generally found
with bituminous coal or in the coal measures, therefore it is mined to
some extent in western Pennsylvania and Ohio. It is an important ore in
England.


=160. The Value of Ores.=—Ores are valued according to the amount
of iron they contain, the physical properties, the cost of mining,
the cost of transportation to the furnace, and their behavior during
reduction. The ores of the Mesaba range in the Lake Superior district
are very rich, and free from many impurities; they are soft and easily
reduced, and as they are found near the surface, they can be mined
with steam shovels. These are great advantages, but the greatest
disadvantage is the fact that the ore is fine and some of it blows out
of the furnace with the escaping gases; this also fouls the heating
stoves and clogs the boiler flues.


=161. Preparation of Ores.=—Most of the ores are used just as they come
from the mines, but in some cases they are put through a preliminary
treatment. This is sometimes done as an advantage and at other times as
a necessity. This treatment is very simple and consists of weathering,
washing, crushing, and roasting.


=162. Weathering= is a common process. Sometimes ores that have been
obtained from the coal measures and others that may contain pyrites
or similar substances are left exposed to the oxidizing influence of
the weather. This separates the shale and the pyrites. The former can
easily be removed, and the latter is partly oxidized and washed away by
the water or rain falling upon it. The ore piles shown in Fig. 149 are
exposed to the atmosphere and partly weathered before being used.


=163. Washing= is also done for the purpose of removing substances
that would retard the smelting process. For instance, the limonite
ores, which are generally mixed with considerable clay or earthy
compositions, are put through an ore washer to remove those substances
before they are charged into the smelting furnace.


=164. Crushing= is done with machinery to reduce to a uniform size such
refractory ores as are mined in rather large lumps. If the ore were
charged into the furnace as mined, the coarseness would allow the gases
to pass through the ore too readily without sufficient action upon it.
Smaller pieces will pack more closely together, thus offering greater
resistance to the blast, and hastening the reduction.


=165. Roasting or calcination= is done to desulphurize ore which
contains an excess of sulphur. It is done also to expel water, carbon
dioxide, or other volatile matter which it may contain. Ore, made more
porous by roasting, exposes a larger surface to the reducing gases. In
the case of magnetic ores, roasting converts the ferrous oxide into
ferric oxide, which lessens the possibility of the iron becoming mixed
with the slag, thereby preventing considerable loss of metal.

Ore is frequently calcined in open heaps, but in more modern practice
stalls or kilns are employed. Where fuel is cheap and space is
abundant, the first process may be used. A layer of coal a few inches
thick is laid on the ground, and a layer of ore is spread upon it; then
coal and ore are laid in alternate layers until the pile is from 4 to 9
feet high. The coal at the bottom is then ignited, and the combustion
extended through the entire mass. If at any time during the operation
the combustion proceeds too rapidly, the pile is dampened with fine
ore and the burning allowed to proceed until all the coal is consumed.
Blackband ore frequently contains enough carbonaceous matter to
accomplish roasting without the addition of any fuel except the first
layer for starting the operation.

When the ore is calcined in stalls, it is placed in a rectangular
inclosure with walls on three sides; these are from 6 to 12 feet high
and are perforated to allow a thorough circulation of air. This method
is very much like that of roasting in open heaps, but less fuel is
necessary, for the draft is under better control and a more perfect
calcination is accomplished.

When the same operation is performed in kilns, it is more economical
in regard to fuel and labor than either of the two methods explained
above. The process is under better control, and a more uniform product
is obtained. The kilns are built in a circular form of iron plates,
somewhat like a smelting furnace and lined with about 14 inches of fire
brick. The most common size of the kilns is about 14 feet in diameter
at the bottom, 20 feet at the widest part, and 18 feet at the top; the
entire height is about 30 feet. They are capable of receiving about
6000 cubic feet of ore.


=166. Fuels.=—A variety of fuels may be used in the blast furnace
reduction process, but the furnace should be modified to suit the
particular quality of fuel. In this country the fuels most used are
coke, charcoal, and anthracite coal. Coke is the most satisfactory and
is more generally used than either of the others. Charcoal is used to
a certain extent on account of its freedom from impurities and because
it is generally considered that iron produced with charcoal is better
for some purposes than that made by using other fuels. Anthracite coal
is used principally in eastern Pennsylvania because the coal mines are
near at hand, and it is therefore the cheapest fuel available. In some
instances a mixture of anthracite and coke is used.


=167. Fluxes.=—The materials that are charged into the furnace with
the ore, to assist in removing injurious elements that it may contain,
are called fluxes. They collect the impurities and form a slag which
floats on top of the molten iron and which is tapped off before the
metal is allowed to run out. The fluxes also assist in protecting the
lining of the furnace by thus absorbing the impurities which would
otherwise attack the lining and destroy it.

Limestone is almost universally employed as a flux, although dolomite
is used also to some extent. The value of limestone as a flux depends
upon its freedom from impurities, such as silicon and sulphur.

Sulphur and phosphorus are two elements which must be kept out of
the product. When there is too much sulphur, the iron is exceedingly
brittle at a dull red heat, although it can be worked at a higher
or lower temperature. It is called red-short iron and makes welding
difficult. With steel, sulphur diminishes the tensile strength and
ductility. If there is too much phosphorus combined with iron, the
metal will crack when hammered cold. Iron of this kind is called
cold-short iron. This metal can be worked, however, at a higher
temperature than can the red-short iron just described.


=168. The Blast.=—The air blown into the furnace to increase and hasten
combustion is called the blast. Formerly when a cold blast was used,
considerable extra fuel was required to heat the air after it entered
the furnace, but a hot blast is used now almost exclusively. The air
is heated by passing through large stoves built for that purpose. The
stoves are heated by burning the waste gases which are generated in the
furnace and which are conducted from the top of the furnace through a
pipe leading into the stoves. Four of these stoves are shown in Fig.
149 at the left of the picture.

[Illustration: FIG. 145.—RUNNING METAL FROM THE BLAST FURNACE TO LADLES
FOR TRANSPORTING TO EITHER THE OPEN HEARTH FURNACE OR THE PIG MOLDER.]


=169. The Reduction or Blast Furnace.=—Fig. 145. The reduction or blast
furnace is almost universally used for the reduction of iron ore. It
is a large barrel-shaped structure, the exterior of which is formed of
iron plates about 1/2 inch thick, bent and riveted together like the
outer shell of a boiler. This is lined with brickwork or masonry, the
inner portion being made of fire brick to protect the furnace from the
intense heat. Figure 146 shows a sectional view of a furnace of this
kind.

[Illustration: FIG. 146.—SECTIONAL VIEW OF A BLAST FURNACE.]

The stack _D_ is supported on a cast-iron ring, which rests on iron
pillars. The hearth _K_ and the boshes _E_ are beneath the stack and
are built independent of it, usually after the stack has been erected.
This is done so that the hearth can be repaired or relined whenever it
becomes injured. The hearth is also perforated for the introduction of
the tuyères _t_, through which the blast enters the furnace from the
blast main _B_. The opening to the downcomer or pipe leading to the
stoves is shown at _A_.

Figure 147 shows the mechanical arrangement at the top of the furnace,
called the bell and hopper, for receiving and admitting the ore flux
and fuel. By lowering the bell _C_ the material is allowed to drop into
the furnace.

[Illustration: FIG. 147.—SECTIONAL VIEW OF THE BELL AND HOPPER.]

The fuel, ore, and flux are charged into the furnace at the top in
alternate layers, as previously explained; the iron settles down
through the boshes, is melted, and drops to the bottom or hearth. The
slag is drawn off at the cinder notch _c_, Fig. 146, after which the
iron is tapped off at the iron notch _g_. Hollow plates _p_ for water
circulation are inserted in the boshes to protect the lining from
burning out too rapidly.

The melted iron runs from the tapping notch into a large groove made
in sand. This groove is called the “sow.” It is connected with smaller
grooves called the “pigs.” Into these the metal runs and forms pig
iron. Considerable sand adheres to pigs thus formed, and as the sand
is objectionable for foundry, Bessemer, and open-hearth purposes, and
as an enormous amount of hand labor is required in breaking up and
removing it, pig molding machines are used. Figure 148 shows one of
these machines with a ladle pouring the metal into it.

The only objection to this method is that the metal is chilled rather
suddenly by the water through which the molds are led. This sudden
chilling causes a structure different from that found in the same
quality of metal molded in the sand and allowed to cool off gradually,
and most foundrymen as well as other users of iron judge the quality
by the appearance of a fracture. On this account machine-molded pigs
are objectionable. It is claimed, however, that some machines in use at
present have overcome this difficulty.

The approximate dimensions of a modern coke-burning furnace are as
follows (see Fig. 146): The hearth _K_ is about 13 feet in diameter
and about 9 feet high. The diameter of the portion above the hearth
increases for about 15 feet to approximately 21 feet in diameter at the
boshes _E_. From the top of the boshes the diameter gradually decreases
until it is about 14 feet in diameter at the stock line. The throat, or
top, where the fuel and ore are charged in through the bell and hopper,
is about 70 feet above the hearth. On the brackets which are connected
to the pillars, the blast main rests, completely surrounding the
furnace, and at numerous places terminal pipes convey the blast to the
tuyères. After the furnace has been charged, or “blown in,” as it is
commonly called, it is kept going continually night and day, or until
it becomes necessary to shut down for repairs.

A general view of a smelting plant is shown in Fig. 149. The four
circular structures to the left with a tall stack between them are
the stoves for heating the blast. Next to these in the center of the
picture is the blast furnace, somewhat obstructed by the conveyor
which carries the ore and fuel to the top for charging. The structural
work to the right is the unloader, which takes the ore from the vessels
and conveys it to the stock pile in the foreground, where the ore is
allowed to drop.

[Illustration: FIG. 148.—PIG MOLDING MACHINE.]


=170. Classification of Pig Iron.=—The pig iron produced by the blast
furnace is graded as to quality, and is known by the following names:
Bessemer, basic, mill, malleable, charcoal, and foundry iron. This
classification indicates the purpose for which each kind is best suited.


=171. Bessemer iron= is that used for making Bessemer steel. In this
grade the amounts of sulphur and phosphorus should be as low as
possible. Bessemer iron is generally understood to contain less than
0.1 per cent of phosphorus and less than .05 per cent of sulphur.


=172. Basic iron= is that which is generally used in the basic process
of steel manufacture. It should contain as little silicon as possible,
because the silicon will attack the basic lining of the furnace;
therefore the surface of the pig iron used for this purpose should, if
possible, be free from sand. By the basic process of making steel, most
of the phosphorus in the pig iron is removed, consequently basic iron
may contain considerably more phosphorus than if it were to be used in
the Bessemer process.


=173. Mill iron= is that which is used mostly in the puddling mill for
the manufacture of wrought iron. It should contain a low percentage of
silicon. Therefore pig iron that has been made when the furnace was
working badly for foundry iron is sometimes used for this purpose.


=174. Malleable iron= is that used for making malleable castings. It
usually contains more phosphorus than Bessemer iron and less than
foundry iron. The percentage of silicon and graphitic carbon is also
very low in this class.


=175. Charcoal iron= is simply that which has been made in a furnace
where charcoal has been used as the fuel. It is generally used as a
foundry iron for special purposes.


=176. Foundry iron= is used for making castings by being melted and
then poured into molds. For this purpose an iron that will readily fill
the mold without much shrinkage in cooling is desired. Other properties
of foundry iron will depend upon the character of the castings desired.


=177. Grading Iron.=—Iron is graded and classified according to its
different properties and qualities by two methods; namely, chemical
analysis and examination of fracture.

Grading by analysis, although not universally used at present, is no
doubt the more perfect method, because the foreign substances contained
in the metal can be accurately determined. Grading by fracture is more
generally used, although it cannot be considered absolutely perfect,
but when done by one who has had years of experience and has trained
his eye to discover the different granular constructions and luster of
the fractured parts, it is very nearly correct; unless the properties
are to be known to an absolute certainty, grading by fracture is
sufficiently accurate for all practical purposes.

[Illustration: FIG. 149.—GENERAL VIEW OF A SMELTING PLANT, SHOWING
BLAST FURNACE STOVES AND THE ORE PILE.]


QUESTIONS FOR REVIEW

  What is ore? Name four grades of iron ore. What is native iron? What
  is the difference between it and other iron ores? What class of ore
  contains the largest percentage of iron? Red hematite contains less,
  so why is it considered more valuable than the magnetite? What amount
  of iron do the limonite and ferrous carbonate ores contain? What
  determines the value of an ore? How is ore prepared for reduction?
  What are the results of these preparations? What are fluxes used for?
  What flux is most generally used? What effect does sulphur produce
  in wrought-iron? What is the effect of phosphorus in wrought-iron?
  How is air heated before it enters the blast furnace? What is the
  difference between sand-molded and machine-molded pig iron? What is
  the objection to machine-molded pig iron? Name the different classes
  of pig iron and state the use of each. How is iron graded?



CHAPTER IX

THE MANUFACTURE OF IRON AND STEEL


=178. Refining Pig Iron.=—Two distinct methods have been adopted for
the conversion of pig iron into wrought iron, each depending upon
the kind of furnace used. They are called the open-hearth or finery
process, and the puddling process. The chemical reactions are similar
in both processes, being based on the oxidation of the impurities in
the metal. This is accomplished both by means of the oxygen in the
air supplied and by the oxide of iron in the fluxes that are added to
assist the operation.


=179. The Open-hearth or Finery Process.=—This is carried on in what is
sometimes termed a “bloomery” from the product which is called a bloom.
The pig iron is placed in direct contact with the fuel on the hearth
which is formed of cast-iron plates exposed to a current of air to keep
them cool. This mixture of the iron with the fuel is objectionable,
because while the fuel acts as a reducer the excess air decarbonizes
the product only partly, besides prolonging the process considerably;
by the addition of hammer scale and rich slag, the operation is
hastened greatly. However, if some carbon is supposed to be contained
in the product, making it of a steely nature, then the open-hearth
process is considered a good method of refining.

Fusion is allowed to take place gradually, so as to expose the metal
for a long period to the oxygen of the blast. At the moment of fusion
the foreign elements are rapidly oxidized and form a fusible slag.
After the slag becomes neutral and has been partly removed, fresh basic
slag and hammer scale are added, to hasten the operation. Then the mass
of iron, which is now of a white spongy texture, is lifted up in the
furnace to a level with the tuyère, in order that the combined carbon
may be completely oxidized. It is then formed into balls of about 60
to 80 pounds each, after which it is removed and formed into a bloom
by means of a squeezer or hammer. This furnace is not illustrated,
because most of the wrought iron is produced by the puddling process.
An open-hearth furnace, such as is used in producing steel, is somewhat
similar to the one here described and is shown in Fig. 163.


=180. The Puddling Process.=—The greatest amount of wrought iron is
produced from pig iron by this process, owing to the superior quality
of the product. The term “puddling” was originally applied to the
process of working iron that had never been completely melted, but
had only reached a puddled or pasty state. But later, when refined or
pig iron was similarly treated, it was discovered that it would melt
perfectly and boil up freely. The process was then termed “pig boiling.”

The furnace used in this process is of the reverberatory type; the fuel
does not come in contact with the iron. (See Fig. 150.) It is built in
a rectangular form; the fireplace _A_ is located at one end, next to it
is the hearth _C_ where the metal is placed, and beyond are the flue
_B_ and the chimney _D_.

From the fireplace the heat is supplied and directed upon the metal by
the top or roof, which is curved downward from the fireplace toward the
flue and chimney. The fireplace also is separated from the hearth by a
partial partition wall _E_, called the fire bridge, which prevents the
fuel from coming in contact with the metal. Another similar partition
_F_, located between the hearth and the flue, prevents the metal from
going into the latter and is called the flue bridge.

[Illustration: FIG. 150.—PUDDLING FURNACE OF A REVERBERATORY TYPE.]

Both of these and all interior portions that come in contact with the
heat and metal are constructed of fire brick. The bridges are built
over hollow iron castings, through the openings of which there is a
circulation of water provided to keep them cool. The bottom of the
hearth is formed of iron plates rabbeted together; this and the sides
are sometimes provided also with hollow castings for water circulation.

The hearth is lined with blue billy and the sides with bulldog. The
former is a fusible silicate, chiefly ferric oxide, and is produced
from tap cinder; it does not readily unite with silica when heated.
Bulldog is made from burnt pyrites, a quality of ore used for the
manufacture of sulphuric acid; the resulting oxide is sometimes called
blue billy, but more frequently bulldog, to distinguish it from the
former class of oxides. Both of these linings are known as fettlings.

The flue slopes down toward the stack; the draft is regulated with a
damper, located in the top and connected by a chain, which hangs within
reach of the operators. Various forms of furnaces are used, such as
stationary and rolling furnaces; but whatever the style of furnace, the
process is based on the decarbonization of the metal, and the charge
of pig iron does not come in direct contact with the fuel, as in the
open-hearth process. An advantage gained in using the puddling furnace
is that various kinds of fuel can be employed without injury to the
product of iron, also various labor-saving devices, which have recently
been invented, can be better used.

In the pig-boiling process the furnace is first lined with the
fettlings and charged with about 500 pounds of white foundry or forge
pig iron. The refining process is divided into four distinct stages
known as melting down, mixing, boiling, and balling.

A very high temperature is desired during the first stage, which
usually lasts about thirty-five minutes. During this time the melting
down occurs, and a partial removal of the silicon from the pig iron is
effected.

In the second or mixing stage, which lasts about seven minutes, a
comparatively low temperature is maintained by lowering the damper
in the stack, while the charge is being thoroughly mixed with the
oxidizing fluxes or cinders that are added. The puddler draws down the
metal from around the sides into the center, where it will become more
rapidly refined and mixed.

During the third or boiling stage the damper is raised to increase
the temperature. At this time a violent reaction occurs, caused by
the release of carbonic oxide, which is formed when the oxygen unites
with the carbon in the pig iron. The gas escapes through the slag on
the surface of the metal, thus causing it to appear as though it were
boiling, from which action the process derives its name. During this
stage, which lasts from twenty to twenty-five minutes, a large portion
of the manganese, sulphur, and phosphorus contained in the pig iron is
removed.

The oxidation is assisted by the constant stirring or rabbling of the
metal by the puddler, done for the purpose of bringing it under the
oxidizing influence of the air. The boiling gradually ceases, and the
surface of the charge “drops,” as it is called, and the whole mass lies
in a pasty state on the bed of the furnace, where it is worked by the
puddler as thoroughly as possible so as to allow the flames to pass
uniformly over it.

The fourth or balling stage requires from fifteen to twenty minutes.
This consists of breaking up the contents into balls weighing from 60
to 80 pounds each. After they have been formed, they are rolled near
the fire bridge to receive a final welding heat before they are removed
to the squeezer, or hammer, where the slag is expelled and the bloom
formed.

The blooms from either the open-hearth or puddling process are treated
similarly in what is termed the forge; this includes hammering,
rolling, and shingling.

[Illustration: FIG. 151.—ROLLING TOOL STEEL.]

Squeezers or hammers are used for forming the bloom and expelling the
inclosed slag. The bloom is then put through the largest groove of the
roughing rolls and passed back through the next smaller, and so on
until it is rolled down to the desired size. Figure 151 shows 14-inch
rolls in use which, although somewhat similar to those employed for
rolling iron, are larger and generally made with more rolls.

The product of this first rolling is not usually considered of superior
quality, so, in order to refine it more thoroughly, the bars are cut
up into short lengths, piled into bundles, reheated, and again welded.
This process is called shingling and is done two or three times,
depending upon the desired quality of iron. This shingling produces the
laminæ of the iron referred to in section 60. For ordinary bar iron the
piles are made about 2 feet long by 4 inches square, and for larger
sizes they may be made 5 or 6 feet long by 10 or 12 inches square.

The rolls are of various kinds. All shapes and sizes of bar iron used
in blacksmithing may be produced in this manner. Rolling machines are
known as two, three, and four high, meaning that they are provided with
that number of rolls, one above the other. Universal rolling machines
have two pairs of rolls in one machine; one pair runs on horizontal
axes and the other on vertical axes. Each pair can be opened or closed
independently, thus giving the machine a wide range.


=181. Steel.=—The word “steel” means very little to those who are
uninformed as to its different qualities and the causes of the
distinctions between them. People are generally familiar with the
various purposes for which steel is used, but know very little about
its nature. There are, however, great differences in the qualities, and
definite reasons for them.

Formerly any combination of iron and carbon that would harden by sudden
cooling or quenching was considered steel. But since modern methods of
manufacturing have been adopted, tons of metal, which would have been
classed as iron if judged by the cooling test, are at present known as
mild or soft steel.

Steel may properly be defined as an alloy of iron with carbon, the
latter not exceeding 1.8 per cent; the materials are completely fused
and poured into molds, allowed to cool, and then rolled into shape.
In the processes of making wrought iron the materials are only partly
fused and are not cast into molds, but are taken out of the furnace in
a soft, pasty condition suitable for immediate working.

The older process of producing “blister” or “cementation” steel is
not generally employed now. By this method the bars of iron were put
through a soaking or prolonged heating, while they were packed in
charcoal. It was similar to the casehardening process, explained in
section 90.

We have at present three notable processes of making steel; namely, the
crucible, Bessemer, and open-hearth.

[Illustration: FIG. 152.—A CRUCIBLE.]

[Illustration: FIG. 153.—SECTIONAL VIEW OF A FOUR-HOLE CRUCIBLE
FURNACE.]


=182. The Crucible Process.=—Crucible furnaces are flat structures
containing from two to twenty holes, each one capable of receiving four
or six crucibles. The crucibles are earthen vessels made of fire clay,
mixed with refractory materials for withstanding intense heat. Each one
is capable of receiving from 70 to 80 pounds of metal. (See Fig. 152.)
In this furnace the gas and air supply may be applied independently to
each hole, practically making each one a separate furnace, but all of
the holes are connected with one main stack or chimney. A sectional
view of a four-hole furnace is shown in Fig. 153, where the crucibles
are shown in position.

This process is the most simple. It consists of melting the stock in
the crucibles and pouring it, when completely fused, into molds, as
shown in Fig. 154, forming what is known as ingots or steel castings.
For that reason it is very frequently called cast steel. The stock is
carefully selected and weighed so as to produce the required grade.
After the ingots are cooled, the piped or hollow ends caused by
shrinkage are broken off and graded by the appearance of the granular
structure and luster of the fractured parts. They are then marked and
piled away for future use. On the ingots shown in Fig. 155, the piped
ends can be seen.

[Illustration: FIG. 154.—POURING STEEL INTO INGOT MOLDS.]

The ingots are heated in an ordinary heating furnace, and rolled or
hammered into suitable bars, the sizes being fixed both by the amount
of carbon contained in the ingots and by the dimensions required for
the manufacture of special tools. Figure 151 shows the workmen in the
act of rolling tool steel; in Fig. 156 they are seen drawing octagon
tool steel with the tilting hammer.

[Illustration: FIG. 155.—STEEL INGOTS.]

[Illustration: FIG. 156.—DRAWING OCTAGON TOOL STEEL WITH THE TILTING
HAMMER.]

Special alloys of crucible steel such as Mushet, blue chip, high speed,
or other special brands are made by the same process, the secret of
the difference lying entirely in the selection of the stock.

[Illustration: FIG. 157.—CROSS SECTION OF A CONVERTER THROUGH THE
TRUNNIONS.]

[Illustration: FIG. 158.—ANOTHER CROSS SECTION OF THE SAME.]


=183. The Bessemer Process.=—This consists of blowing air through
molten pig iron in a vessel called a converter, sectional views of
which are shown in Figs. 157 and 158. A converter is a pear-shaped
structure hung on trunnions _A_, _A_, so that it can be tipped forward.
The air is forced through one of the trunnions, which is hollow, and
is connected with a pipe which conveys the air to the air chamber _f_
at the bottom of the converter. The bottom grate or tuyère plate is
located directly above the air chamber, and through the openings _j_,
_j_, in the tuyère plate, the air passes up through the metal.

[Illustration: FIG. 159.—POURING METAL INTO MOLDS.]

[Illustration: FIG. 160.—INGOT STRIPPER.]

The converter is tipped forward into a horizontal position while
the molten metal is poured into it. The air is then turned on, and
the converter is raised to a perpendicular position. The air passes
up through the entire charge of iron; consequently the metal is
thoroughly acted upon, while in the open-hearth process it is not.
The Bessemer process is based on oxidation; it produces a very high
temperature and keeps the charge in a liquid state during the time
of blowing. This is continued until the sulphur and phosphorus are
removed or the charge becomes decarbonized,—a condition termed burned
steel, owing to the presence of dissolved oxygen. This condition is
then changed or recarbonized by adding manganese alloys, such as
spiegeleisen or ferromanganese, which give the necessary amount of
carbon. By these additions the iron is changed into steel.

The Bessemer process requires a very short time in comparison with
the puddling process. Three tons of pig iron can be refined in about
twenty minutes, while by the puddling process the same amount of metal
requires about twenty-four hours.

[Illustration: FIG. 161.—LOWERING AN INGOT INTO THE SOAKING PIT.]

Considerable excitement was caused at the time the process was
invented, not only on account of the time saved, but also because there
was such a great saving in fuel.

After the metal has been poured from the converter into molds similar
to those shown in Fig. 159, and has cooled sufficiently to become
solid, the molds are stripped off, as shown in Fig. 160, and the
ingots of metal placed in the soaking pits, Fig. 161. These pits are
somewhat similar to a crucible furnace and are used for reheating
ingots before they are slabbed or rolled. Such a furnace is generally
made of the regenerative type and is divided into several compartments,
each one capable of receiving several ingots which are inserted on end.

[Illustration: FIG. 162.—A BLOOMING MILL.]

From the pit furnace the ingots are taken and rolled into slabs, rails,
blooms, or other forms suitable for use. When the plant is equipped
with both blast furnace and converter, this is all done without
additional heating, but when the plant is not so equipped, the pig iron
is melted in a cupola furnace before being put into the converter. A
blooming mill is shown in operation in Fig. 162.

[Illustration: FIG. 163.—OPEN-HEARTH FURNACE, FROM THE CHARGING SIDE.]

[Illustration: FIG. 164.—SECTIONAL VIEW OF AN OPEN-HEARTH FURNACE.]


=184. The Open-hearth Process.=—Fig. 163. Here again the process
depends on the type of furnace. Open-hearth steel is produced with a
reverberatory furnace, and the heat is supplied by regenerative gas
and air. The furnace is built mostly of brickwork with the exception
of the supporting beams, doors, tie rods, and hearth castings, which
are made of cast iron, wrought iron, or steel. All brickwork that comes
in contact with the intense heat is made of silica brick, manufactured
from rock crystals, flint, or other varieties of quartz rock with about
two per cent of quicklime. The roof of the furnace slopes toward the
center, so that when the air and gas enter they are directed downward
on the charge of metal. The bottom or hearth is constructed of heavy
steel plates riveted together and supported on I beams. This bottom is
first covered with a layer of brick, then sand is applied to about
the thickness of one inch and well rammed down, then other layers of
brick and sand are added until the thickness is about 14 to 16 inches.
This bottom requires repairing with more sand between successive heats.
Figure 164 shows a cross section through the center of the charging and
discharging openings.

[Illustration: FIG. 165.—ANOTHER SECTIONAL VIEW OF AN OPEN-HEARTH
FURNACE.]

When the furnace has been charged, the gas and air are allowed to enter
at intervals of fifteen minutes, first from one side, then from the
other. When the air and gas enter one side, the exhaust or waste gases
pass out through the other side. The reversing is done by means of
levers which open and close the valves. A sectional view is given in
Fig. 165, showing the air and gas chambers and the brick checker work
through which the air and gas pass and are heated. The broken lines
represent the passages leading to these chambers; the valves are also
shown.

[Illustration: FIG. 166.—OPEN-HEARTH FURNACE DISCHARGING.]

When the metal has been fused sufficiently, a sample is dipped out
and analyzed, so that its composition may be known and sufficient
carbonizing material added to produce the desired quality. This is not
possible with the Bessemer process. It is finally tapped into a large
ladle, from which it is poured into molds forming the ingots, which
are treated in the same way as described in the Bessemer process. The
discharging is shown in Fig. 166.


QUESTIONS FOR REVIEW

  What methods are used for converting pig iron into wrought iron?
  Describe in full the two methods. What other name is sometimes given
  to the puddling process? Why is it so named? Explain the process
  of puddling. How is the first product of the puddling process
  treated? What is the object of this treatment? What is steel? Name
  the different qualities, giving the approximate carbon contents of
  each. What is the old test for iron and steel? How was “blister”
  steel produced? By what process is cast or tool steel made? What sort
  of vessel is used in melting the materials? State the differences
  between making tool and soft steel. What is an ingot? What is the
  difference between an ingot of tool steel and an ingot of soft steel?
  What is meant by the piped end of a tool steel ingot? How are these
  ingots classified? How is octagon tool steel made? What processes
  are used in making soft steel? Describe each. Which is the most
  satisfactory? Which is the most rapid? Why is the product of the
  open-hearth process the best? What is the purpose of “soaking” the
  ingots?



FORMULAS AND TABLES

(From the “Pocket Companion,” published by the Carnegie Steel Co.)


1. WEIGHTS

The average weight of wrought iron is 480 pounds per cubic foot. A bar
1 inch square and 3 feet long weighs, therefore, exactly 10 pounds. The
weight of steel is 2 per cent greater than the weight of wrought iron,
or 489.6 pounds. Cast iron weighs 450 pounds to the cubic foot.


2. LENGTHS

  Circumference of circle = diameter × 3.1416.
  Diameter of circle = circumference × 0.3183.
  Side of square of equal periphery as circle = diameter × 0.7854.
  Diameter of circle of equal periphery as square = side × 1.2732.
  Side of an inscribed square = diameter of circle × 0.7071.
  Length of arc = number of degrees × diameter × 0.008727.


3. AREAS

  Triangle = base × half altitude.
  Parallelogram = base × altitude.
  Trapezoid = half the sum of the parallel sides × altitude.
  Trapezium, found by dividing into two triangles.
  Circle = square of diameter × 0.7854; or,
         = square of circumference × 0.07958.
  Sector of circle = length of arc × half radius.


4. STANDARD DIMENSIONS OF NUTS AND BOLTS

  Short diameter of rough nut = 1-1/2 × diameter of bolt + 1/8 inch.
  Short diameter of finished nut = 1-1/2 × diameter of bolt + 1/16 inch.
  Thickness of rough nut = diameter of bolt.
  Thickness of finished nut = diameter of bolt − 1/16 inch.
  Short diameter of rough head = 1-1/2 × diameter of bolt + 1/8 inch.
  Short diameter of finished head = 1-1/2 × diameter of bolt
                                      + 1/16 inch.
  Thickness of rough head = 1/2 short diameter of head.
  Thickness of finished head = diameter of bolt − 1/16 inch.


5. DECIMALS OF AN INCH FOR EACH 1/64TH

  ========+==========+==========+==========
  1/32ds. | 1/64ths. | Decimal  | Fraction
  --------+----------+----------+----------
          |    1     |  .015625 |
     1    |    2     |  .03125  |
          |    3     |  .046875 |
     2    |    4     |  .0625   |  1/16
          |          |          |
          |    5     |  .078125 |
     3    |    6     |  .09375  |
          |    7     |  .109375 |
     4    |    8     |  .125    |  1/8
          |          |          |
          |    9     |  .140625 |
     5    |   10     |  .15625  |
          |   11     |  .171875 |
     6    |   12     |  .1875   |  3/16
          |          |          |
          |   13     |  .203125 |
     7    |   14     |  .21875  |
          |   15     |  .234375 |
     8    |   16     |  .25     |  1/4
          |          |          |
          |   17     |  .265625 |
     9    |   18     |  .28125  |
          |   19     |  .296875 |
    10    |   20     |  .3125   |  5/16
          |          |          |
          |   21     |  .328125 |
    11    |   22     |  .34375  |
          |   23     |  .359375 |
    12    |   24     |  .375    |  3/8
          |          |          |
          |   25     |  .390625 |
    13    |   26     |  .40625  |
          |   27     |  .421875 |
    14    |   28     |  .4375   |  7/16
          |          |          |
          |   29     |  .453125 |
    15    |   30     |  .46875  |
          |   31     |  .484375 |
    16    |   32     |  .5      |  1/2
          |          |          |
          |   33     |  .515625 |
    17    |   34     |  .53125  |
          |   35     |  .546875 |
    18    |   36     |  .5625   |  9/16
          |          |          |
          |   37     |  .578125 |
    19    |   38     |  .59375  |
          |   39     |  .609375 |
    20    |   40     |  .625    |  5/8
          |          |          |
          |   41     |  .640625 |
    21    |   42     |  .65625  |
          |   43     |  .671875 |
    22    |   44     |  .6875   |  11/16
          |          |          |
          |   45     |  .703125 |
    23    |   46     |  .71875  |
          |   47     |  .734375 |
    24    |   48     |  .75     |  3/4
          |          |          |
          |   49     |  .765625 |
    25    |   50     |  .78125  |
          |   51     |  .796875 |
    26    |   52     |  .8125   |  13/16
          |          |          |
          |   53     |  .828125 |
    27    |   54     |  .84375  |
          |   55     |  .859375 |
    28    |   56     |  .875    |  7/8
          |          |          |
          |   57     |  .890625 |
    29    |   58     |  .90625  |
          |   59     |  .921875 |
    30    |   60     |  .9375   |  15/16
          |          |          |
          |   61     |  .953125 |
    31    |   62     |  .96875  |
          |   63     |  .984375 |
    32    |   64     | 1.       |  1
  ========+==========+==========+==========


6. WEIGHTS OF FLAT ROLLED STEEL PER LINEAR FOOT

One cubic foot weighing 489.6 pounds

  =======+======+======+======+=======+=======+=======+=======+======
  Thick- |      |  1-  |  1-  |   1-  |       |   2-  |   2-  |   2-
  ness in|  1″  | 1/4″ | 1/2″ |  3/4″ |   2″  |  1/4″ |  1/2″ |  3/4″
  inches |      |      |      |       |       |       |       |
 --------+------+------+------+-------+-------+-------+-------+------
   3/16  | .638 | .797 | .957 |  1.11 |  1.28 |  1.44 |  1.59 |  1.75
   1/4   | .850 | 1.06 | 1.28 |  1.49 |  1.70 |  1.91 |  2.12 |  2.34
         |      |      |      |       |       |       |       |
   5/16  | 1.06 | 1.33 | 1.59 |  1.86 |  2.12 |  2.39 |  2.65 |  2.92
   3/8   | 1.28 | 1.59 | 1.92 |  2.23 |  2.55 |  2.87 |  3.19 |  3.51
   7/16  | 1.49 | 1.86 | 2.23 |  2.60 |  2.98 |  3.35 |  3.72 |  4.09
   1/2   | 1.70 | 2.12 | 2.55 |  2.98 |  3.40 |  3.83 |  4.25 |  4.67
         |      |      |      |       |       |       |       |
   9/16  | 1.92 | 2.39 | 2.87 |  3.35 |  3.83 |  4.30 |  4.78 |  5.26
   5/8   | 2.12 | 2.65 | 3.19 |  3.72 |  4.25 |  4.78 |  5.31 |  5.84
  11/16  | 2.34 | 2.92 | 3.51 |  4.09 |  4.67 |  5.26 |  5.84 |  6.43
   3/4   | 2.55 | 3.19 | 3.83 |  4.47 |  5.10 |  5.75 |  6.38 |  7.02
         |      |      |      |       |       |       |       |
  13/16  | 2.76 | 3.45 | 4.14 |  4.84 |  5.53 |  6.21 |  6.90 |  7.60
   7/8   | 2.98 | 3.72 | 4.47 |  5.20 |  5.95 |  6.69 |  7.44 |  8.18
  15/16  | 3.19 | 3.99 | 4.78 |  5.58 |  6.38 |  7.18 |  7.97 |  8.77
    1    | 3.40 | 4.25 | 5.10 |  5.95 |  6.80 |  7.65 |  8.50 |  9.35
         |      |      |      |       |       |       |       |
  1-1/16 | 3.61 | 4.52 | 5.42 |  6.32 |  7.22 |  8.13 |  9.03 |  9.93
  1-1/8  | 3.83 | 4.78 | 5.74 |  6.70 |  7.65 |  8.61 |  9.57 | 10.52
  1-3/16 | 4.04 | 5.05 | 6.06 |  7.07 |  8.08 |  9.09 | 10.10 | 11.11
  1-1/4  | 4.25 | 5.31 | 6.38 |  7.44 |  8.50 |  9.57 | 10.63 | 11.69
         |      |      |      |       |       |       |       |
  1-5/16 | 4.46 | 5.58 | 6.69 |  7.81 |  8.93 | 10.04 | 11.16 | 12.27
  1-3/8  | 4.67 | 5.84 | 7.02 |  8.18 |  9.35 | 10.52 | 11.69 | 12.85
  1-7/16 | 4.89 | 6.11 | 7.34 |  8.56 |  9.78 | 11.00 | 12.22 | 13.44
  1-1/2  | 5.10 | 6.38 | 7.65 |  8.93 | 10.20 | 11.48 | 12.75 | 14.03
         |      |      |      |       |       |       |       |
  1-9/16 | 5.32 | 6.64 | 7.97 |  9.30 | 10.63 | 11.95 | 13.28 | 14.61
  1-5/8  | 5.52 | 6.90 | 8.29 |  9.67 | 11.05 | 12.43 | 13.81 | 15.19
 1-11/16 | 5.74 | 7.17 | 8.61 | 10.04 | 11.47 | 12.91 | 14.34 | 15.78
  1-3/4  | 5.95 | 7.44 | 8.93 | 10.42 | 11.90 | 13.40 | 14.88 | 16.37
         |      |      |      |       |       |       |       |
 1-13/16 | 6.16 | 7.70 | 9.24 | 10.79 | 12.33 | 13.86 | 15.40 | 16.95
  1-7/8  | 6.38 | 7.97 | 9.57 | 11.15 | 12.75 | 14.34 | 15.94 | 17.53
 1-15/16 | 6.59 | 8.24 | 9.88 | 11.53 | 13.18 | 14.83 | 16.47 | 18.12
    2    | 6.80 | 8.50 |10.20 | 11.90 | 13.60 | 15.30 | 17.00 | 18.70
 ========+======+======+======+=======+=======+=======+=======+======
  Thick- |      |  3-  |  3-  |   3-  |       |   4-  |   4-  |   4-
  ness in|  3″  | 1/4″ | 1/2″ |  3/4″ |   4″  |  1/4″ |  1/2″ |  3/4″
  inches |      |      |      |       |       |       |       |
  -------+------+------+------+-------+-------+-------+-------+------
   3/16  | 1.91 | 2.07 | 2.23 |  2.39 |  2.55 |  2.71 |  2.87 |  3.03
   1/4   | 2.55 | 2.76 | 2.98 |  3.19 |  3.40 |  3.61 |  3.83 |  4.04
         |      |      |      |       |       |       |       |
   5/16  | 3.19 | 3.45 | 3.72 |  3.99 |  4.25 |  4.52 |  4.78 |  5.05
   3/8   | 3.83 | 4.15 | 4.47 |  4.78 |  5.10 |  5.42 |  5.74 |  6.06
   7/16  | 4.46 | 4.83 | 5.20 |  5.58 |  5.95 |  6.32 |  6.70 |  7.07
   1/2   | 5.10 | 5.53 | 5.95 |  6.38 |  6.80 |  7.22 |  7.65 |  8.08
         |      |      |      |       |       |       |       |
   9/16  | 5.74 | 6.22 | 6.70 |  7.17 |  7.65 |  8.13 |  8.61 |  9.09
   5/8   | 6.38 | 6.91 | 7.44 |  7.97 |  8.50 |  9.03 |  9.57 | 10.10
  11/16  | 7.02 | 7.60 | 8.18 |  8.76 |  9.35 |  9.93 | 10.52 | 11.11
   3/4   | 7.65 | 8.29 | 8.93 |  9.57 | 10.20 | 10.84 | 11.48 | 12.12
         |      |      |      |       |       |       |       |
  13/16  | 8.29 | 8.98 | 9.67 | 10.36 | 11.05 | 11.74 | 12.43 | 13.12
   7/8   | 8.93 | 9.67 |10.41 | 11.16 | 11.90 | 12.65 | 13.39 | 14.13
  15/16  | 9.57 |10.36 |11.16 | 11.95 | 12.75 | 13.55 | 14.34 | 15.14
    1    |10.20 |11.05 |11.90 | 12.75 | 13.60 | 14.45 | 15.30 | 16.15
         |      |      |      |       |       |       |       |
  1-1/16 |10.84 |11.74 |12.65 | 13.55 | 14.45 | 15.35 | 16.26 | 17.16
  1-1/8  |11.48 |12.43 |13.39 | 14.34 | 15.30 | 16.26 | 17.22 | 18.17
  1-3/16 |12.12 |13.12 |14.13 | 15.14 | 16.15 | 17.16 | 18.17 | 19.18
  1-1/4  |12.75 |13.81 |14.87 | 15.94 | 17.00 | 18.06 | 19.13 | 20.19
         |      |      |      |       |       |       |       |
  1-5/16 |13.39 |14.50 |15.62 | 16.74 | 17.85 | 18.96 | 20.08 | 21.20
  1-3/8  |14.03 |15.20 |16.36 | 17.53 | 18.70 | 19.87 | 21.04 | 22.21
  1-7/16 |14.66 |15.88 |17.10 | 18.33 | 19.55 | 20.77 | 21.99 | 23.22
  1-1/2  |15.30 |16.58 |17.85 | 19.13 | 20.40 | 21.68 | 22.95 | 24.23
         |      |      |      |       |       |       |       |
  1-9/16 |15.94 |17.27 |18.60 | 19.92 | 21.25 | 22.58 | 23.91 | 25.24
  1-5/8  |16.58 |17.96 |19.34 | 20.72 | 22.10 | 23.48 | 24.87 | 26.25
  1-11/16|17.22 |18.65 |20.08 | 21.51 | 22.95 | 24.38 | 25.82 | 27.26
  1-3/4  |17.85 |19.34 |20.83 | 22.32 | 23.80 | 25.29 | 26.78 | 28.27
         |      |      |      |       |       |       |       |
  1-13/16|18.49 |20.03 |21.57 | 23.11 | 24.65 | 26.19 | 27.73 | 29.27
  1-7/8  |19.13 |20.72 |22.31 | 23.91 | 25.50 | 27.10 | 28.69 | 30.28
  1-15/16|19.77 |21.41 |23.06 | 24.70 | 26.35 | 28.00 | 29.64 | 31.29
  2      |20.40 |22.10 |23.80 | 25.50 | 27.20 | 28.90 | 30.60 | 32.30
  =======+======+======+======+=======+=======+=======+=======+======
  Thick- |      |  5-  |  5-  |   5-  |       |
  ness in|  5″  | 1/4″ | 1/2″ |  3/4″ |   6″  |  12″
  inches |      |      |      |       |       |
  -------+------+------+------+-------+-------+------
    3/16 | 3.19 | 3.35 | 3.51 |  3.67 |  3.83 |  7.65
    1/4  | 4.25 | 4.46 | 4.67 |  4.89 |  5.10 | 10.20
         |      |      |      |       |       |
    5/16 | 5.31 | 5.58 | 5.84 |  6.11 |  6.38 | 12.75
    3/8  | 6.38 | 6.69 | 7.02 |  7.34 |  7.65 | 15.30
    7/16 | 7.44 | 7.81 | 8.18 |  8.56 |  8.93 | 17.85
    1/2  | 8.50 | 8.93 | 9.35 |  9.77 | 10.20 | 20.40
         |      |      |      |       |       |
    9/16 | 9.57 |10.04 |10.52 | 11.00 | 11.48 | 22.95
    5/8  |10.63 |11.16 |11.69 | 12.22 | 12.75 | 25.50
   11/16 |11.69 |12.27 |12.85 | 13.44 | 14.03 | 28.05
    3/4  |12.75 |13.39 |14.03 | 14.67 | 15.30 | 30.60
         |      |      |      |       |       |
   13/16 |13.81 |14.50 |15.19 | 15.88 | 16.58 | 33.15
    7/8  |14.87 |15.62 |16.36 | 17.10 | 17.85 | 35.70
   15/16 |15.94 |16.74 |17.53 | 18.33 | 19.13 | 38.25
     1   |17.00 |17.85 |18.70 | 19.55 | 20.40 | 40.80
         |      |      |      |       |       |
  1-1/16 |18.06 |18.96 |19.87 | 20.77 | 21.68 | 43.35
  1-1/8  |19.13 |20.08 |21.04 | 21.99 | 22.95 | 45.90
  1-3/16 |20.19 |21.20 |22.21 | 23.22 | 24.23 | 48.45
  1-1/4  |21.25 |22.32 |23.38 | 24.44 | 25.50 | 51.00
         |      |      |      |       |       |
  1-5/16 |22.32 |23.43 |24.54 | 25.66 | 26.78 | 53.55
  1-3/8  |23.38 |24.54 |25.71 | 26.88 | 28.05 | 56.10
  1-7/16 |24.44 |25.66 |26.88 | 28.10 | 29.33 | 58.65
  1-1/2  |25.50 |26.78 |28.05 | 29.33 | 30.60 | 61.20
         |      |      |      |       |       |
  1-9/16 |26.57 |27.89 |29.22 | 30.55 | 31.88 | 63.75
  1-5/8  |27.63 |29.01 |30.39 | 31.77 | 33.15 | 66.30
  1-11/16|28.69 |30.12 |31.55 | 32.99 | 34.43 | 68.85
  1-3/4  |29.75 |31.24 |32.73 | 34.22 | 35.70 | 71.40
         |      |      |      |       |       |
  1-13/16|30.81 |32.35 |33.89 | 35.43 | 36.98 | 73.95
  1-7/8  |31.87 |33.47 |35.06 | 36.65 | 38.25 | 76.50
  1-15/16|32.94 |34.59 |36.23 | 37.88 | 39.53 | 79.05
     2   |34.00 |35.70 |37.40 | 39.10 | 40.80 | 81.60
  =======+======+======+======+=======+=======+======


7. WEIGHTS AND AREAS OF SQUARE AND ROUND BARS AND CIRCUMFERENCES OF
ROUND BARS

  =========+=========+=========+==========+==========+===========
  Thickness|Weight of|Weight of| Area of  | Area of  |Circumfer-
     or    |[square] | [round] | [square] | [round]  |ence  of
   Diameter| Bar one | Bar one |  Bar in  |  Bar in  |[round] Bar
  in inches|foot long|foot long|sq. inches|sq. inches|in inches
  ---------+---------+---------+----------+----------+-----------
     1/16  |    .013 |   .010  |   .0039  |   .0031  |   .1963
     1/8   |    .053 |   .042  |   .0156  |   .0123  |   .3927
     3/16  |    .119 |   .094  |   .0352  |   .0276  |   .5890
           |         |         |          |          |
     1/4   |    .212 |   .167  |   .0625  |   .0491  |   .7854
     5/16  |    .333 |   .261  |   .0977  |   .0767  |   .9817
     3/8   |    .478 |   .375  |   .1406  |   .1104  |  1.1781
     7/16  |    .651 |   .511  |   .1914  |   .1503  |  1.3744
           |         |         |          |          |
     1/2   |    .850 |   .667  |   .2500  |   .1963  |  1.5708
     9/16  |   1.076 |   .845  |   .3164  |   .2485  |  1.7671
     5/8   |   1.328 |  1.043  |   .3906  |   .3068  |  1.9635
    11/16  |   1.608 |  1.262  |   .4727  |   .3712  |  2.1598
           |         |         |          |          |
     3/4   |   1.913 |  1.502  |   .5625  |   .4418  |  2.3562
    13/16  |   2.245 |  1.763  |   .6602  |   .5185  |  2.5525
     7/8   |   2.603 |  2.044  |   .7656  |   .6013  |  2.7489
    15/16  |   2.989 |  2.347  |   .8789  |   .6903  |  2.9452
           |         |         |          |          |
    1      |   3.400 |  2.670  |  1.0000  |   .7854  |  3.1416
     1/16  |   3.838 |  3.014  |  1.1289  |   .8866  |  3.3379
     1/8   |   4.303 |  3.379  |  1.2656  |   .9940  |  3.5343
     3/16  |   4.795 |  3.766  |  1.4102  |  1.1075  |  3.7306
           |         |         |          |          |
     1/4   |   5.312 |  4.173  |  1.5625  |  1.2272  |  3.9270
     5/16  |   5.857 |  4.600  |  1.7227  |  1.3530  |  4.1233
     3/8   |   6.428 |  5.049  |  1.8906  |  1.4849  |  4.3197
     7/16  |   7.026 |  5.518  |  2.0664  |  1.6230  |  4.5160
           |         |         |          |          |
     1/2   |   7.650 |  6.008  |  2.2500  |  1.7671  |  4.7124
     9/16  |   8.301 |  6.520  |  2.4414  |  1.9175  |  4.9087
     5/8   |   8.978 |  7.051  |  2.6406  |  2.0739  |  5.1051
    11/16  |   9.682 |  7.604  |  2.8477  |  2.2365  |  5.3014
           |         |         |          |          |
     3/4   |  10.41  |  8.178  |  3.0625  |  2.4053  |  5.4978
    13/16  |  11.17  |  8.773  |  3.2852  |  2.5802  |  5.6941
     7/8   |  11.95  |  9.388  |  3.5156  |  2.7612  |  5.8905
    15/16  |  12.76  | 10.02   |  3.7539  |  2.9483  |  6.0868
           |         |         |          |          |
    =2=    |  13.60  | 10.68   |  4.0000  |  3.1416  |  6.2832
     1/16  |  14.46  | 11.36   |  4.2539  |  3.3410  |  6.4795
     1/8   |  15.35  | 12.06   |  4.5156  |  3.5466  |  6.6759
     3/16  |  16.27  | 12.78   |  4.7852  |  3.7583  |  6.8722
           |         |         |          |          |
     1/4   |  17.22  | 13.52   |  5.0625  |  3.9761  |  7.0686
     5/16  |  18.19  | 14.28   |  5.3477  |  4.2000  |  7.2649
     3/8   |  19.18  | 15.07   |  5.6406  |  4.4301  |  7.4613
     7/16  |  20.20  | 15.86   |  5.9414  |  4.6664  |  7.6576
           |         |         |          |          |
     1/2   |  21.25  | 16.69   |  6.2500  |  4.9087  |  7.8540
     9/16  |  22.33  | 17.53   |  6.5664  |  5.1572  |  8.0503
     5/8   |  23.43  | 18.40   |  6.8906  |  5.4119  |  8.2467
    11/16  |  24.56  | 19.29   |  7.2227  |  5.6727  |  8.4430
           |         |         |          |          |
     3/4   |  25.    | 20.20   |  7.5625  |  5.9396  |  8.6394
    13/16  |  26.90  | 21.12   |  7.9102  |  6.2126  |  8.8357
     7/8   |  28.10  | 22.07   |  8.2656  |  6.4918  |  9.0321
    15/16  |  29.34  | 23.04   |  8.6289  |  6.7771  |  9.2284
           |         |         |          |          |
    =3=    |  30.60  | 24.03   |  9.0000  |  7.0686  |  9.4248
     1/16  |  31.89  | 25.04   |  9.3789  |  7.3662  |  9.6211
     1/8   |  33.20  | 26.08   |  9.7656  |  7.6699  |  9.8175
     3/16  |  34.55  | 27.13   | 10.160   |  7.9798  |  10.014
           |         |         |          |          |
     1/4   |  35.92  | 28.20   | 10.563   |  8.2958  |  10.210
     5/16  |  37.31  | 29.30   | 10.973   |  8.6179  |  10.407
     3/8   |  38.73  | 30.42   | 11.391   |  8.9462  |  10.603
     7/16  |  40.18  | 31.56   | 11.816   |  9.2806  |  10.799
           |         |         |          |          |
     1/2   |  41.65  | 32.71   | 12.250   |  9.6211  |  10.996
     9/16  |  43.14  | 33.90   | 12.691   |  9.9678  |  11.192
     5/8   |  44.68  | 35.09   | 13.141   | 10.321   |  11.388
    11/16  |  46.24  | 36.31   | 13.598   | 10.680   |  11.585
           |         |         |          |          |
     3/4   |  47.82  | 37.56   | 14.063   | 11.045   |  11.781
    13/16  |  49.42  | 38.81   | 14.535   | 11.416   |  11.977
     7/8   |  51.05  | 40.10   | 15.016   | 11.793   |  12.174
    15/16  |  52.71  | 41.40   | 15.504   | 12.177   |  12.370
           |         |         |          |          |
    =4=    |  54.40  | 42.73   | 16.000   | 12.566   |  12.566
     1/16  |  56.11  | 44.07   | 16.504   | 12.962   |  12.763
     1/8   |  57.85  | 45.44   | 17.016   | 13.364   |  12.959
     3/16  |  59.62  | 46.83   | 17.535   | 13.772   |  13.155
           |         |         |          |          |
     1/4   |  61.41  | 48.24   | 18.063   | 14.186   |  13.352
     5/16  |  63.23  | 49.66   | 18.598   | 14.607   |  13.548
     3/8   |  65.08  | 51.11   | 19.141   | 15.033   |  13.744
     7/16  |  66.95  | 52.58   | 19.691   | 15.466   |  13.941
           |         |         |          |          |
     1/2   |  68.85  | 54.07   | 20.250   | 15.904   |  14.137
     9/16  |  70.78  | 55.59   | 20.816   | 16.349   |  14.334
     5/8   |  72.73  | 57.12   | 21.391   | 16.800   |  14.530
    11/16  |  74.70  | 58.67   | 21.973   | 17.257   |  14.726
           |         |         |          |          |
     3/4   |  76.71  | 60.25   | 22.563   | 17.721   |  14.923
    13/16  |  78.74  | 61.84   | 23.160   | 18.190   |  15.119
     7/8   |  80.81  | 63.46   | 23.766   | 18.665   |  15.315
    15/16  |  82.89  | 65.10   | 24.379   | 19.147   |  15.512
           |         |         |          |          |
    =5=    |  85.00  | 66.76   | 25.000   | 19.635   |  15.708
     1/16  |  87.14  | 68.44   | 25.629   | 20.129   |  15.904
     1/8   |  89.30  | 70.14   | 26.266   | 20.629   |  16.101
     3/16  |  91.49  | 71.86   | 26.910   | 21.135   |  16.297
           |         |         |          |          |
     1/4   |  93.72  | 73.60   | 27.563   | 21.648   |  16.493
     5/16  |  95.96  | 75.37   | 28.223   | 22.166   |  16.690
     3/8   |  98.23  | 77.15   | 28.891   | 22.691   |  16.886
     7/16  | 100.5   | 78.95   | 29.566   | 23.221   |  17.082
           |         |         |          |          |
     1/2   | 102.8   | 80.77   | 30.250   | 23.758   |  17.279
     9/16  | 105.2   | 82.62   | 30.941   | 24.301   |  17.475
     5/8   | 107.6   | 84.49   | 31.641   | 24.850   |  17.671
    11/16  | 110.0   | 86.38   | 32.348   | 25.406   |  17.868
           |         |         |          |          |
     3/4   | 112.4   | 88.29   | 33.063   | 25.967   |  18.064
    13/16  | 114.9   | 90.22   | 33.785   | 26.535   |  18.261
     7/8   | 117.4   | 92.17   | 34.516   | 27.109   |  18.457
    15/16  | 119.9   | 94.14   | 35.254   | 27.688   |  18.653
  =========+=========+=========+==========+==========+===========


8. CIRCUMFERENCES AND CIRCULAR AREAS OF NUMBERS FROM 1 TO 100

  ====+=============================
      |      Number = Diameter
  No. +---------------+-------------
      | Circumference |     Area
  ----+---------------+-------------
    1 |      3.142    |      0.7854
    2 |      6.283    |      3.1416
    3 |      9.425    |      7.0686
    4 |     12.566    |     12.5664
    5 |     15.708    |     19.6350
      |               |
    6 |     18.850    |     28.2743
    7 |     21.991    |     38.4845
    8 |     25.133    |     50.2655
    9 |     28.274    |     63.6173
   10 |     31.416    |     78.5398
      |               |
   11 |     34.558    |     95.0332
   12 |     37.699    |    113.097
   13 |     40.841    |    132.732
   14 |     43.982    |    153.938
   15 |     47.124    |    176.715
      |               |
   16 |     50.265    |    201.062
   17 |     53.407    |    226.980
   18 |     56.549    |    254.469
   19 |     59.690    |    283.529
   20 |     62.832    |    314.159
      |               |
   21 |     65.973    |    346.361
   22 |     69.115    |    380.133
   23 |     72.257    |    415.476
   24 |     75.398    |    452.389
   25 |     78.540    |    490.874
      |               |
   26 |     81.681    |    530.929
   27 |     84.823    |    572.555
   28 |     87.965    |    615.752
   29 |     91.106    |    660.520
   30 |     94.248    |    706.858
      |               |
   31 |     97.389    |    754.768
   32 |    100.531    |    804.248
   33 |    103.673    |    855.299
   34 |    106.814    |    907.920
   35 |    109.956    |    962.113
      |               |
   36 |    113.097    |   1017.88
   37 |    116.239    |   1075.21
   38 |    119.381    |   1134.11
   39 |    122.522    |   1194.59
   40 |    125.66     |   1256.64
      |               |
   41 |    128.81     |   1320.25
   42 |    131.95     |   1385.44
   43 |    135.09     |   1452.20
   44 |    138.23     |   1520.53
   45 |    141.37     |   1590.43
      |               |
   46 |    144.51     |   1661.90
   47 |    147.65     |   1734.94
   48 |    150.80     |   1809.56
   49 |    153.94     |   1885.74
   50 |    157.08     |   1963.50
      |               |
   51 |    160.22     |   2042.82
   52 |    163.36     |   2123.72
   53 |    166.50     |   2206.18
   54 |    169.65     |   2290.22
   55 |    172.79     |   2375.83
      |               |
   56 |    175.93     |   2463.01
   57 |    179.07     |   2551.76
   58 |    182.21     |   2642.08
   59 |    185.35     |   2733.97
   60 |    188.50     |   2827.43
   61 |    191.64     |   2922.47
   62 |    194.78     |   3019.07
   63 |    197.92     |   3117.25
   64 |    201.06     |   3216.99
   65 |    204.20     |   3318.31
      |               |
   66 |    207.35     |   3421.19
   67 |    210.49     |   3525.65
   68 |    213.63     |   3631.68
   69 |    216.77     |   3739.28
   70 |    219.91     |   3848.45
      |               |
   71 |    223.05     |   3959.19
   72 |    226.19     |   4071.50
   73 |    229.34     |   4185.39
   74 |    232.48     |   4300.84
   75 |    235.62     |   4417.86
      |               |
   76 |    238.76     |   4536.46
   77 |    241.90     |   4656.63
   78 |    245.04     |   4778.36
   79 |    248.19     |   4901.67
   80 |    251.33     |   5026.55
      |               |
   81 |    254.47     |   5153.00
   82 |    257.61     |   5281.02
   83 |    260.75     |   5410.61
   84 |    263.89     |   5541.77
   85 |    267.04     |   5674.50
      |               |
   86 |    270.18     |   5808.80
   87 |    273.32     |   5944.68
   88 |    276.46     |   6082.12
   89 |    279.60     |   6221.14
   90 |    282.74     |   6361.73
      |               |
   91 |    285.88     |   6503.88
   92 |    289.03     |   6647.61
   93 |    292.17     |   6792.91
   94 |    295.31     |   6939.78
   95 |    298.45     |   7088.22
      |               |
   96 |    301.59     |   7238.23
   97 |    304.73     |   7389.81
   98 |    307.88     |   7542.96
   99 |    311.02     |   7697.69
  100 |    314.16     |   7853.98
  ====+===============+==============



INDEX

[Figures in italics indicate pages upon which illustrations occur.]


  Andirons and bar, _159_.

  Angle blow, _see_ beveling blow.

  Annealing, 86, 87.

  Anvil, 5, _6_, 7.

  Areas, formulas of, 197.

  Art smithing, 146.


  Backing-up blow, _35_, _36_.

  “Backing-up” metal, _43_.

  Banding with clips, 147.

  Basic iron, 174.

  Bellows, 1.

  Bench and measuring tools, 22-28.

  Bench vise, _22_, 23.

  Bending, 40, 41;
    stock calculation for, 118-121.

  Bending or twisting fork, _149_;
    wrench, _150_, 151.

  Bessemer iron, 173;
    process, 187-193.

  Bevel, _25_, 26.

  Beveling blow, 32, _33_, 34.

  Bevel or taper tool, _135_.

  Blackband, 164.

  Blast, 168-170.

  Blast furnace, _see_ reduction furnace.

  Blister steel, 184.

  Block, swage, 19, _20_.

  Bloomery, 177.

  Blooming mill, _191_.

  Blue billy, 180.

  Blue chip, 186.

  Bolsters, _136_.

  Bolt, hexagonal head, 66, _67_.

  Boring tools, _103_, 104.

  Box tongs, _see_ tool tongs.

  Brass tool, _101_, 102.

  Brown hematite, _see_ limonite.

  Bulldog, 180.

  Burned steel, 189.

  Butterfly scarf, 115, _116_, 117.

  Button head set, _19_.

  Butt weld, _52_, 53.


  Calcination, _see_ roasting.

  Calipers, _25_, 26, 118, _119_.

  Cape chisel, _24_.

  Carbon, percentage of, in tool steel, 83-85.

  Casehardening, 92, 93.

  Cast steel, 185.

  Cementation steel, _see_ blister steel.

  Center punch, _24_, 25.

  Chain grabhook, _80_, _81_, 82.

  Chain making, _73_, 74.

  Chain swivel, _76_-80.

  Charcoal, 5, 167.

  Charcoal iron, 174.

  Checking tool or side fuller, _130_, 131.

  Chisel, trimming, _127_, 128.

  Chisels, 23, _24_, _108_, 109.

  Chisel tongs _10_, 11.

  Circular cutter, _127_.

  Circumferences and circular areas of numbers from 1 to 100: 205, 206.

  Classification of pig iron, 173.

  Clay ironstone, 164.

  Cleft weld, _52_, 53.

  Clincher, _see_ clip tightener.

  Clip, 148.

  Clip former, _151_, 152;
    holder, _152_, 153;
    tightener or clincher, _153_, 154.

  Coal box, 1.

  Coke, 5, 167.

  Cold chisel, 23, _24_, _89_, _108_, 109.

  Cold cutters, _12_, 13, _110_, 111, _128_-130.

  Collars, _see_ bolsters.

  Colored oxides, 88, 89.

  Combination fuller and set, _132_, 133.

  Combined spring fullers, _131_, 132;
    top and bottom swages, _133_, 134.

  Connecting lever, _142_, 143;
    rod, 138, _139_.

  Converter, _187_, 188.

  Crank shaft, 137, _138_.

  Crowbar, steel-faced, _113_, 114.

  Crucible, _184_.

  Crucible process, 184-187.

  Crucible steel, alloys of, 186.

  Crushing, 166.

  Cutter, _see_ hack.
   circular, _127_;
   cold, _12_, 13, _128_-130;
   hardening, 14;
   hot, _12_, 13, 14, _109_, 110.

  Cutting-off or parting tool, _102_, 103.

  Cutting stock, 128, _129_, 130.


  Decimals of an inch for each 1/64th, 198.

  Designing, 146.

  Diamond point tool, _104_-106.

  Dies, 43, 123, 124.

  Dimensions of nuts and bolts, 197.

  Dipper, _4_.

  Dividers, _25_, 26.

  Dolomite as a flux, 168.

  Door hasp, 64-66.

  Double and single offsets, 143-145.

  Double-faced sledge, _9_.

  Drawing, 37-40.

  Draw spike, _59_.

  Drop hammer, 123, 124.


  Eccentric jaw, _140_, 141.

  Edge-to-edge blow, _31_, 32.

  Eye or ring bolts, 114, _115_, 116-118.


  Fagot welding, 69.

  Ferromanganese, 189.

  Ferrous carbonate, 164.

  Fettlings, 180.

  Files, _27_, 28.

  Finery process, _see_ open-hearth process.

  “Finished,” definition of, 137.

  Fire cracks, 85.

  Fire set, _159_, 160;
    separated, 160.

  Fire tools, _4_.

  Flat-jawed tongs, _10_.

  Flat right-angled weld, 70, _71_, 72.

  Flatter, 14, _15_, _112_, 113.

  Fluxes, 167, 168.

  Forge, XII, 1-3.

  Forging, definition of, 36-37.

  Forging, operations used in, 36-47.

  Forgings, 123.

  Forging tools, 12-28, 107-118.

  Forming, 43, 44.

  Formulas and tables, 197-206.

  Foundry iron, 174.

  Franklinite, 162.

  Fuels, 4, 5, 48, 49, 167.

  Fullers, combined spring, _131_, 132;
    top and bottom, _18_, 19.


  Gate hook, 62, _63_, 64.

  Grabhook, _80_, _81_, 82.

  Grading iron, 174, 176.


  Hack or cutter, _126_, 127.

  Hack saw, _27_.

  Hammer blows, 30-36.

  Hammers, 7, 8;
    ball peen, _8_;
    cross peen, _8_;
    drop, 123, 124;
    hand, 8;
    round and square-edged set, _15_, 16, _111_;
    steam, 124, _125_, 126;
    straight peen, _8_.

  Handle punches, _16_, 17.

  Hand lever, _141_, 142.

  Hardening tool steel, 87-92;
    wrought iron and soft steel, 92, 93.

  Hardy, _12_, 13, 111, _112_.

  Hasp, door, 64-66.

  Heading tool, _19_.

  Heating, 48-50.

  Heating air for blast furnace, 168-170;
    tool steel, 85, 86.

  Heavy boring tool, _103_;
    flat tongs, 96, _97_, 98.

  Hollow bit tongs, _10_, 11.

  Hot cutter, _12_-14, _109_, 110.


  Ingots, 185, 186.

  Ingot stripper, _189_.

  Injuries to steel, 85.

  Iron, cold-short, 168;
    colors and temperatures for, 94;
    distribution of, 162;
    native, 161;
    red-short, 168;
    welding, 47;
    wrought, 178.

  Iron ore, 161-162;
    ferrous carbonate a form of, 164;
    limonite a form of, 163, 164;
    magnetite a form of, 162, 163;
    nickel in, 161;
    red hematite a form of, 163.

  Iron oxide in flux, 177.


  Jardinière stand or taboret, _154_-157.

  Jarring, _see_ upsetting by jarring.

  Jump weld, _53_, 54.


  Kiln, 167.


  Lap weld, _50_-52.

  Lathe tools, 101-107.

  Lengths, formulas of, 197.

  Leverage blow, _34_, 35.

  Light boring tool, 103, 104;
    chain tongs, 98-101.

  Limonite, 163, 164.

  Link tongs, _10_, 11.


  Machine forgings, 137-145.

  Magnetite, 162, 163.

  Malleable iron, 174.

  Manual training forge, _2_, _3_.

  Material for welding, 47, 48.

  Meteorites, 161.

  Mild steel, 183.

  Mill iron, 174.

  Mushet, 186.


  Nasmyth, James, 124.

  Native iron, 161.


  Offsets, _143_-145.

  Open eye, 114, _115_.

  Open-hearth furnace, _192_, _193_, _194_, _195_.

  Open-hearth process, 177, 178, 193-196.

  Ore, definition of, 161.

  Ores, preparation of, 165;
    value of, 164, 165.

  Overhanging blow, _32_.

  Oxides, colored, 88, 89.

  Oxidizing fire, 49.


  Parting tool, _see_ cutting-off tool.

  Phosphorus in iron, 168.

  Pick-up tongs, _10_, 11.

  Pig boiling, 178.

  Pig iron, classification of, 173.

  Pig molding machine, 171-_173_.

  Pigs, cast-iron, 171.

  Pipe hook, 60, _61_, 62.

  Plug punch, use of, _136_.

  Preparation of ores, 165.

  Presses, 124.

  Puddling process, 178, _179_-183.

  Punches, _16_, 17, _24_, 25, _136_, 137.

  Pure iron, 162.


  Questions for review, 28, 29, 57, 82, 95, 121, 122, 145,
      160, 176, 196.

  Ramming, _see_ upsetting by ramming.

  Reading lamp, _158_, 159.

  Red hematite, 163.

  Reducing fire, 49, 50.

  Reduction furnace, _170_-173.

  Refining pig iron, 177.

  Refining process, four stages of, 180, 181.

  Refining steel, 88.

  Reverberatory furnace, description of, _179_, 193, 194.

  Right side tool, _106_, 107.

  Ring bolts, _see_ eye bolts.

  Riveting, 147, 148.

  Roasting ore, 166, 167.

  Rod strap, 139, _140_.

  Rolling machines, 183.

  Rolling tool steel, _182_.

  Round-edged set hammer, _15_, 16, _112_, 113.

  Round weld, 69, _70_.

  Rule, _24_, 25.


  Saddle, _see_ yoke.

  Scarfing, 50.

  Scriber or scratch awl, _25_, 26.

  Scroll bending, _150_;
    fastenings, 147, 148;
    former, _148_, _149_.

  Shearing blow, 36, _37_.

  Shingling, 182.

  Ship-smith eye, _117_, 118.

  S hook, 59, _60_.

  Side fuller, _see_ checking tool.

  Side tongs, _10_, 11;
    tool, _106_, _107_.

  Slag, 168.

  Sledges, _9_.

  Snap, _see_ button head set.

  Solid forged, eye, _117_, 118;
    ring, _143_.

  Spathic ore, 164, 165.

  Spiegeleisen, 163, 164, 189, 190.

  Spring fullers, _131_.

  Spring swages, _see_ combined top and bottom swages.

  Square, _25_, 26.

  Square-cornered angle, 67-_69_.

  Square-edged set hammer, _15_, 16, _111_.

  Standard dimensions of nuts and bolts, 197.

  Staple, _58_.

  Steam hammer, 124, 125.

  Steam hammer tools, 126-137.

  Steam hammer work, exercises in, 137-145.

  Steel, 183-196.

  Steel, kind of, suitable for tools, 83.

  Steel, tool, 83-95;
    annealing of, 86, 87;
    colors on surface of, 88, 89;
    injuries to, 85, 86:
    hardening and tempering of, 87-92;
    oil-tempered, 90;
    percentage of carbon in, 83-85;
    proper and improper heating of, 85, 86;
    proper and improper treatment of, _91_, 92;
    temperature and color charts for, 94;
    two methods of hardening and tempering, 89, 90;
    water annealing of, 87;
    welding of, 48.

  Steel, uses of different grades of, 84, 85.

  Stock calculation for bonding, 118-121.

  Straightening, _44_, _45_.

  Sulphur in iron and steel, 168.

  Surface plate, 20, _21_.

  Swage block, 19, _20_.

  Swages, combined top and bottom, _133_, 134;
    top and bottom, _17_, 18, 134.

  Swing sledge, _see_ double-faced sledge.

  Swivels, _76_-80.


  Tapered mandrels, 21, _22_.

  Taper tool, _see_ bevel tool.

  Tempering, temperature and color chart for, 94.

  Tempering heat as determined by colors, 88-91;
    by scientific apparatus, 91, 92.

  Tempering tool steel, 87-92.

  Threading tool, _see_ light boring tool.

  Tilting hammer, _186_.

  Tongs, 9, _10_, 11, 12, 96-101;
    chisel, _10_, 11;
    flat-jawed, _10_;
    heavy flat, 96, _97_, 98;
    hollow bit, _10_, 11;
    light chain, 98, _99_, _100_, 101;
    link, _10_, 11;
    pick-up, _10_, 11:
    side, _10_, 11;
    tool, _10_,11.

  Tool, checking, _130_, 131;
    for welding a swivel, _76_;
    heading, _19_.

  Tools, bench and measuring, 22-28;
   fire, _4_;
   forging, 12-28, 107-118;
   lathe, 101-107.

  Tool tongs, _10_, 11.

  Top and bottom, fullers, _18_, 19;
    swages, _133_, 134.

  Trimming chisel, _127_, 128.

  Tuyère, 3, 187, 188.

  T weld, _72_, 73.

  Twisting, 45, _46_.

  Twisting wrench, _see_ bending wrench.


  Umbrella stand, 157, _158_, 159.

  Upright blow, _30_, 31.

  Upsetting, 41-43;
    by “backing-up,” _43_;
    by hammering, _42_, 43;
    by jarring, _43_;
    by ramming, _43_.


  Value of ores, 164-165.

  V block, _135_.

  Vise, bench, _22_, 23.

  V weld, _54_-56.


  Washing ore, 165.

  Water swaging, 18.

  Weathering ore, 165.

  Weights and areas of square and round bars, 202-204.

  Weights, formulas of, 197.

  Weights of flat rolled steel per linear foot, 199-201.

  Welded ring, 74, _75_, 76.

  Welding, 46, 47, 147;
    fagot, 69;
    heat, 51, 52;
    material for, 47, 48.

  Welds, 50-56, 69-73;
    butt, _52_, 53;
    cleft, _52_, 53;
    flat right-angled, 70, _71_, 72;
    jump, _53_, 54;
    lap, _50_-52;
    round, 69, _70_;
    T, _72_, 73;
    V, _54_-56.


  Yoke or saddle, 135, _136_.





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