This specification has been declared NONCURRENT by the Aerospace Materials Division, SAE, as of April, 2005. It is recommended, therefore, that this specification not be specified for new designs. NONCURRENT refers to those specifications which have previously been widely used and which may be required for production or processing of existing designs in the future. The Aerospace Materials Division, however, does not recommend these specifications for future use in new designs.

This specification covers a premium aircraft-quality alloy steel in the form of plate.

This plate has been used typically for heat treated parts requiring a combination of high strength, high toughness, and weldability, but usage is not limited to such applications.