本规范涵盖标称厚度小于等于8英寸（203 mm）的手工锻件和锻坯形式的铝合金。这些锻件通常用于机加工过程中容易发生翘曲、要求高强度和抗应力腐蚀开裂的机加工结构零件，但其用途不限于此类应用。

This specification covers an aluminum alloy in the form of hand forgings 8 inches (203 mm) and under in nominal thickness, and of forging stock.These forgings have been used typiclaly for machined structural parts subject to warpage during machining and requiring high strength and resistance to stress-corrosion cracking, but usage is not limited to such applications.