本标准涵盖了与各种类型的螺钉和固定垫圈组件（也称为SEM）相关的一般数据和尺寸数据。（sems是一个通用术语，适用于螺钉和垫圈组件。）

This Standard covers the general, dimensional, material, and mechanical requirements for metric through-hardened (property classes 8.8, 9.8, and 10.9) machine screws and case-hardened tapping screws from 5 mm to 12 mm captivated washer assemblies (SEMS). The covered washer types are helical, plain, conical, and toothed.This Standard describes two different methods of SEMS manufacturing. It also covers standard and modified hardness requirements for machine screw SEMS.The inclusion of dimensional data in this Standard is not intended to imply that all of the products described herein are stock production items. Consumers should consult with respective suppliers concerning the availability of products.In addition, this Standard includes Nonmandatory Appendices that contain information considered of significant importance to both purchaser and manufacturer.