This section is from the book "An Elementary Outline Of Mechanical Processes", by G. W. Danforth. Also available from Amazon: An elementary outline of mechanical processes.
These are usually made from octagon-bar steel, hardened at the cutting ends. The two forms most used are the flat chisel A, and the cape chisel B, shown in Fig. 206. The blade of B is much narrower than that of A. Other forms, as the half-round and V-cornered, are very useful.