Mecasteel 145 (minimum yield strength 145 ksi) is a high-strength prehardened steel that can be used in substitution for conventional steels, such as AISI 4330, in the manufacture of massive steel components such as machines, hydraulic systems, and pumps. This datasheet provides information on composition and tensile properties as well as fracture toughness. It also includes information on forming. Filing Code: SA-691. Producer or source: Industeel USA, LLC. Revised as Alloy Digest SA-703, July 2014.