This specification covers an aluminum alloy in the form of extruded profiles (shapes).These extrusions have been used typically for machined parts requiring dimensional stability during machining processes, with high strength and damage tolerance, but usage is not limited to such applications. This product maintains fine unrecrystallised peripheral grain even though significant cold work precedes the solution heat treatment.Certain processing procedures may cause this product to become susceptible to stress-corrosion cracking; SAE ARP 823 recommends practices to minimize such conditions.