Abstract Crucible CPM Rex 76 (HS) is a superhigh-speed steel that can be heat treated to very high hardness levels. It is made by the Crucible Particle Metallurgy (CPM) process. This datasheet provides information on composition, physical properties, hardness, and elasticity. It also includes information on forming, heat treating, machining, and surface treatment. Filing Code: TS-304. Producer or source: Crucible Service Centers Divisional Headquarters. Originally published July 1976, revised 2006.