This specification has been declared "NONCURRENT" by the Aerospace Materials Division, SAE, as of September 1996. It is recommended, therefore, that this specification not be specified for new designs. This specification covers a premium aircraft-quality, low-alloy steel in the form of sheet, strip, and plate. These products have been used typically for parts, such as pressure vessels, requiring through-hardening to high strength levels and where such parts may require welding during fabrication, but usage is not limited to such applications.