① 由制造商選擇添加元素。

注1： “全尺寸”指的拉力測試試件是使用前的狀态未經改變的完整的緊固件產品。
注2：A——Machined from annealed or solution-annealed stock thus retaining the properties of the original material, or hot-formed and solution-annealed.
AF——Headed and rolled from annealed stock and then reannealed.
AH——Solution annealed and age-hardened after forming.
CW——Headed and rolled from annealed stock thus acquining a degree of cold work; sizes 0.75 in. and larger may be hot worked and solution-annealed.
H——Hardened and tempered at 1050°F (565℃) minimum.
HT——Hardened and tempered at 525°F (274℃) minimum.
SH——Machined from strain hardened stock or cold-worked to develop the specified properties.