本规范涵盖标称直径小于等于4.0英寸（102 mm）或平行边之间最小距离小于等于4.0平方英寸（103 cm2）的锻件形式的钛合金，以及任何尺寸的锻件坯料（见8.6）。

This specification covers a titanium alloy in the form of forgings up through 4.0 inches (102 mm) and under in nominal diameter or least distance between parallel sides and 16 square inches (103 cm2) and under in cross-sectional area and stock of any size for forging (see 8.6).