本标准旨在涵盖被公认为美国国家标准的各类开槽和凹头机螺钉、自攻螺钉和金属传动螺钉的完整通用和尺寸数据。还包括附录，其中提供了平沉头螺钉凸出测量的规范和说明；六角头螺钉的交叉测量；凹头螺钉的穿透测量和摆动测量；自攻螺钉的近似孔尺寸；六角和方形产品的扳手开口；0000号、000号和00号尺寸的螺纹尺寸；确定螺钉上有效夹持长度的方法；属于不推荐或限制使用状态的螺钉类型和螺钉头类型的文件；以及维度数据所依据的公式。 但是，应理解，如果出现有关产品验收的问题，应以表格中的尺寸为准，而不是通过公式重新计算。

This Standard is intended to cover the complete general and dimensional data for the various types of slotted and recessed head machine screws, tapping screws, and metallic drive screws recognized as American National Standard. Also included are appendices that provide specifications and instructions for the protrusion gaging of flat countersunk head screws; across-corners gaging of hex head screws; penetration gaging and wobble gaging of recessed head screws; approximate hole size for tapping screws; wrench openings for hex and square products; thread dimensions for the No. 0000, No. 000, and No. 00 sizes; means for determining effective grip lengths on screws; documentation for screw types and head types relegated to not-recommended or limited usage status; and formulas on which dimensional data are based. It shall be understood, however, that where questions arise concerning acceptance of product, the dimensions in the tables shall govern over recalculation by formula.