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.
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 13⁄4 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.)