CPM Rex T15 is a tungsten-type high-speed steel containing high carbon and vanadium for very high hardness and maximum wear resistance, and cobalt for good red hardness. It is now made exclusively by Crucible’s particle metallurgy process, resulting in improved quality and grindability. This alloy was designed for use in difficult machining operations requiring heavy-duty cuts, high speeds and feeds, and for difficult-to-machine materials that are high in hardness and abrasion resistance. This datasheet revision updates chemistry, properties, and the benefits of high sulfur (HS). This datasheet provides information on composition, physical properties, hardness, elasticity, and bend strength as well as fracture toughness. It also includes information on wear resistance as well as forming, heat treating, and machining. Filing Code: TS-249. Producer or source: Crucible Service Centers. Originally published as CPM REX T15, January 1973, revised March 2007.