Form This specification covers an aluminum alloy in the form of extruded bars@ rods@ and profiles 0.250 to 2.000 .inches (6.35 to 50.80 mm) in nominal thickness and up to 32 in2 (206 cm2)@ inclusive@ in cross-sectional area (see 8.5). Application These extrusions have been used typically for structural applications requiring a combination of high tensile properties@ moderate fatigue strength@ stress-corrosion resistance@ and good fracture toughness@ but usage is not limited to such applications.