LSS H12 is a general-purpose hot work tool steel with excellent impact toughness. This datasheet provides information on composition, physical properties, hardness, and elasticity as well as fracture toughness. It also includes information on wear resistance as well as heat treating and machining. Filing Code: TS-706. Producer or source: Latrobe Specialty Steel Company. See also Alloy Digest TS-686, January 2010.