This specification has been declared NONCURRENT by the Aerospace Materials Division, SAE, as of February 1998. It is recommended, therefore, that this specification not be specified for new designs. NONCURRENT refers to those materials which have previously been widely used and which may be required on some existing designs in the future. The Aerospace Materials Division, however, does not recommend these as standard materials for future use in new designs.This specification covers a low-alloy steel in the form of investment castings. Primarily for parts of thin to moderately thick cross-section which require heat treatment to minimum tensile strengths up to 180,000 psi (1240 MPa).