=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.