In shops where bolt-making is of frequent occurrence a special bolt-making device is usually employed. It consists of an oliver or foot hammer, having two hammers and an anvil; in the square hole at one end of the anvil fits a hardy or bottom chisel, such as shown in [Fig. 2908], for cutting up the bar or rod iron into bolt blanks; a is the anvil, h the hardy, and g a gauge to determine the length cut off the rod r to form a blank. An upsetting or heading device corresponding to that in [Fig. 2907] is provided, and at the other end of the anvil is the swage for forming the bolt head.
The object of having two hammers is that one may be used for the upsetting of the blank and the other for the swage. The swaging hammer is provided with a hole and set-screw to receive top swages, and bolt hammers are adjustable for height so that they may be set so that their faces will meet the work fair.
Fig. 2909.
Fig. 2910.
