规定了主要用于螺纹紧固件的单头平行粗螺距系列公制螺纹的要求。外螺纹的公差等级为6e、6f、6g和8g，包括直径为1.6 mm至64 mm（含64 mm）的螺纹；内螺纹为6H和6G。给出了有关螺纹参数、公差、偏差、螺纹等级、名称和验证符号的信息。附录中给出了有关螺纹生产的注释，以及本标准和1972年版中使用的符号的比较。应特别注意的是，在本版本中，外螺纹的螺纹根部（根部曲率及相关限制和公差）的规定方式与1972年版有根本不同。

Specifies requirements for single start parallel coarse pitch series metric screw threads, mainly intended for threaded fasteners. It covers screw threads from 1.6 mm diameter up to and including 64 mm diameter, in tolerance classes 6e, 6f, 6g and 8g, for external threads; and 6H and 6G for internal threads. Information is given on symbols for screw thread parameters, tolerances, deviations, thread classes, designation and verification. Appendices, giving notes on the production of screw threads and a comparison of symbols used in This Standard and the 1972 edition, are included. It should be particularly noted that in this edition, the thread roots of external threads (root curvature and associated limits and tolerances), are specified in a manner that is fundamentally different from the 1972 edition.