Form This specification covers an aluminum alloy in the form of extruded bars@ rods@ and profiles up to 0.499 inches (12.67 mm) in nominal diameter@ or least thickness@ and under 10 in2 (65 cm2) in cross-sectional area. Application These extrusions have been used typically for parts in structural applications requiring strength similar to 7050-T6 alloy with good exfoliation resistance and approximately 7.8% lower density@ but usage is not limited to such applications.