This specification covers an aluminum alloy in the form of extruded bars, rods, and profiles (shapes) from 0.375 to 1.300 inches (9.53 to 33.02 mm) in diameter or thickness, produced with cross sectional area of 22.5 in² (145 cm²) maximum, and a circumscribing circle diameter (circle size) of 17.4 inches (44.2 cm) maximum. See 8.3 for definition of circumscribing circle size.