In [Figure 69] is shown a drawing of an open link. Open links are used in the splicing of broken chains. In splicing a chain, the link is opened by driving a chisel between the laps, or it is opened when made. These laps are hooked into links of broken chain and then driven together. In making the link, one end is drawn to a flat point and a hook is hammered on it. See [Figure 70]. The other end is heated and drawn out as in [Figure 71]. The center of the piece is now heated and bent over the horn of the anvil to the desired shape. See [Figure 72]. Notice in the drawing that the hooks at the open end of the link are not very long. They should not be made longer than shown.
Fig. 72.
Exercise No. 8.—Welding a Chain Link.
The form and length of the stock for this exercise is shown in [Figure 73]. The link may be made from iron or soft steel. After the stock is cut, it is heated in the center and bent over the horn of the anvil into a “U” shape. See [Figure 74]. The ends are now heated and scarfed by setting them on the anvil as shown in [Figure 75]. The iron is then struck on top with the hand hammer. After each blow, it is moved away from the anvil just a little, giving the end a bevel, so that, when finished, the scarf consists of a series of slanting notches.
Fig. 73. Fig. 74.
In scarfing, both ends of the links are set on the anvil. The end of the one on the right hand side must not be moved when scarfing the other. After each blow of the hammer, the piece is moved just a little. If it is moved too far and the other end of the link is fixed it will describe an arc. See [Figure 76]. This is the method used in scarfing links. Sometimes they are welded without scarfing, but it is not good practice.
Fig. 75. Fig. 76.