1.1 本规范 2. 涵盖了螺栓、螺柱和其他外螺纹零件上用于一般结构和机械用途的11个等级的碳钢和合金钢螺母的化学、机械和尺寸要求。 注1: 请参阅 附录X1 用于指导螺母等级的适当应用。 1.2 供应商可选择并通知买方，通过提供本文规定的较硬等级之一的螺母来满足任何等级螺母的要求，除非询价和采购订单中禁止此类替代。 1.3 本规范中使用的术语在术语表中定义 1789年 除非本文另有定义。 1.4 以国际单位制或英寸-磅单位表示的值应单独视为标准值。每个系统中所述的值不一定是完全等效的；因此，为确保符合标准，每个系统应独立使用，两个系统的值不得组合。 1.5 本国际标准是根据世界贸易组织技术性贸易壁垒委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认的标准化原则制定的。

1.1 This specification 2 covers chemical, mechanical, and dimensional requirements for eleven grades of carbon and alloy steel nuts for general structural and mechanical uses on bolts, studs, and other externally threaded parts. Note 1: See Appendix X1 for guidance on suitable application of nut grades. 1.2 The requirements for any grade of nut may, at the supplier's option, and with notice to the purchaser, be fulfilled by furnishing nuts of one of the stronger grades specified herein unless such substitution is barred in the inquiry and purchase order. 1.3 Terms used in this specification are defined in Terminology F1789 unless otherwise defined herein. 1.4 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined. 1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.