High-speed steel (HSS or HS) is a subset of tool steels, commonly used as cutting tool material. It is often used in power-saw blades and drill bits. It is superior to the older high-carbon steel tools used extensively through the 1940s in that it can withstand higher temperatures without losing its temper (hardness).
The oxide layer produced is porous thereby retaining oil which lowers friction in ferrous applications, thus avoiding the problems of pick-up, cold welding on taps and ‘built-up edge’ on cutting edges.
