This specification has been declared "NONCURRENT" by the Aerospace Materials Division, SAE, as of January, 1991. 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 Matierials Division, however, does not recommend these as standard materials for future use in new designs.