This specification has been declared "NONCURRENT" by the Aerospace Materials Division, SAE, as of February, 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 on some existing designs in the future. The Aerospace Materials Division, however, does not recommend these specifications for future use in new designs. This specification covers an aluminum alloy in the form of flat sheet and plate 0.500 inch (12.70 mm) and under in nominal thickness. Primarily for structural parts requiring a combination of good strength and maximum corrosion resistance. These products, when re-solution heat treated by the user, may not have the tensile properties shown. Certain design and processing procedures may cause these products to become susceptible to stress-corrosion cracking; ARP 823 recommends practices to minimize such conditions.