Rings and chains are made in a manner similar to that used for eyebolts. The metal is cut off to the proper length and the ends are scarfed as shown in Fig. 50. It is then bent to the desired form of link or ring and the scarfed surfaces brought together. After reheating to the proper temperature, the weld is made. In making chains, the links are successively bent through the one preceding and then welded in position.
Tool Dressing is usually considered one of the most particular jobs in a shop. The work is light and a helper is always used for the striking. The material used is known as tool steel. It is a high grade of metal and contains a large amount of combined carbon. The details of this steel are given in " Metallurgy." Tools are of many shapes. Nearly all those used in a machine shop can be made with a fuller ami flatter. The shank of the tool is usually left the full size of the untouched bar. This statement applies to the lathe and planer tools and cold chisels. The machine tools are made of steel having a rectangular section. Cold chisels and punches are commonly made of octagonal steel.
As an example of a tool to be forged take what is known as a "front tool." This tool is shown in Fig. 71. The metal used is of a size suited to enter the tool post of the lathe for which it is intended. The metal is drawn out and the hollow a made with the fuller. The point b is shaped by the hammer and cut to an approximate shape with a hot chisel. It is well to grind the tool into a working shape before tempering. It should not, however, be sharpened.
Cold chisels are made by simply flattening one end of a bar of (preferably hexagonal) steel and grinding to a suitable edge.
Double ended or sizing cutters are usually made in the machine shop and sent to the blacksmith shop for hardening. The steel of which such tools are made is first cut off and annealed in the blacksmith shop.
Tools for woodworking machinery are first cut from the bar and annealed. They are then shaped and afterwards hardened.