STROLOY 503-A is a hypereutectoid steel of bearing quality. It has through-hardening characteristics similar to those of AISI 52100 steel. Stroloy 503-A is made in accordance with ASTM A 295-84. It is used principally in ball bearing applications. This datasheet provides information on composition and hardness. It also includes information on forming, heat treating, and machining. Filing Code: SA-406. Producer or source: Babcock & Wilcox Company. See also Alloy Digest SA-281, October 1972.