Michael Faraday?s early metallurgic researches, from 1818 to 1824, anticipated the developments which have led to widespread use today of alloy steels. Much effort has been expended to improve their performance for their service as cutting tools in machining. The aim has always been to yield higher rates of machining and to tackle recently developed harder materials on the principle that the tool material must be harder than the workpiece which is to be machined.