CARPENTER NO. 158 ALLOY is a chromium-nickel carburizing steel ideally suited for jobs requiring an extra measure of core strength in sections up to 5 inches thick. Additionally, the steel develops high wear resistant case characteristics when carburized and hardened. This datasheet provides information on composition, physical properties, elasticity, and tensile properties. Filing Code: SA-37. Producer or source: Carpenter. Originally published January 1956, revised May 1991.