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ОглавлениеPREFACE
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.
DEDICATED
TO THE MEMORY OF
MR. DAVID GORRIE
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.
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.
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.
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.
