Cold chisels are made from carbon tool-steel, which is usually octagonal in cross-section.
Tool-steel is used as it can be hardened to form a hard and tough cutting edge.
To make a cold chisel heat the end of the bar of tool steel until it is bright red and hammer to the desired shape.
The cross-section of chisel should be octagonal.
The cutting edge of a chisel should be Hardened and tempered.
A chisel is a tool with a characteristically shaped cutting edge of blade on its end, for carving or cutting a hard material such as wood, stone, or metal by hand, struck with a mallet, or mechanical power.
cape chisel is a cold chisel that has a long taper on the top and bottom of the cutting end and a narrow edge and is used for cutting keyways and similar flat grooves.
A diamond pointed chisel is used for cutting V-shaped grooves.