A few secrets of the metallurgist simply told

by Gerald W. Hinkley

CARBON.

Carbon has already been discussed under Carbon Steels, although, of course, its importance in Alloy Steels must not be under-estimated. The proportion of carbon aimed at in high speed tool steels is about 0.65%, which in simple steel would not be enough to give the maximum hardness, even if the steel were heated above the critical point and quenched in water, and still less so when the steel is cooled as slowly as these steels are in their treatment. This shows that the carbon element acts in a different way from what it does in simple carbon steels as previously discussed.