Form This specification covers an aluminum alloy in the form of plate 3.000 to 7.000 inches (76.20 to 177.80 mm) in nominal thickness (see 8.5). Application This product may be used in aerospace applications requiring a high level of mechanical properties and fracture toughness@ good resistance to stress-corrosion cracking and resistance to exfoliation corrosion@ but usage is not limited to such applications.