This specification covers an aluminum alloy in the form of sheet and plate. These products have been used typically for parts requiring high strength up to 500 φF (260 φC), but usage is not limited to such applications. Product may be welded in the specified condition but properties are improved by reheat treatment after welding. Reheat treatment after welding, however, may reduce resistance to stress-corrosion cracking. Certain design and processing procedures may cause these products to become susceptible to stress-corrosion cracking; ARP823 recommends practices to minimize such conditions.