Form: 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. Application: These products have been used typically 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; ARP823 recommends practices to minimize such conditions.