This specification covers an aluminum alloy in the form of extruded bars, rods, and profiles (shapes) produced with nominal thickness up to 3.000 inches (76.20 mm), inclusive, and having a cross-sectional area of 42 square inches (271 cm²) maximum and a circumscribing circle diameter (circle size) of 15 inches (38 cm) maximum (see 2.4.1 and 8.8).