本标准包含以下通用公制标准: 基本ISO 68-1的60度对称螺纹 配置文件指定为M配置文件。螺纹的M型线 公差等级6H/6g适用于公制应用 其中使用了2A/2B级英寸。在 最低材料限制，6H/6g会导致更宽松的 比2A/2B更合适。此外，还提供了表格数据以供参考 公差更紧的4g6g级外螺纹 大约相当于英寸3A级，但 申请津贴。配方和公差数据 适用于需要其他配合的应用。

This Standard contains general metric standards for a 60 deg symmetrical screw thread with a basic ISO 68-1 profile designated M profile. The M profile threads of tolerance class 6H/6g are intended for metric applications where inch class 2A/2B have been used. At the minimum material limits, the 6H/6g results in a looser fit than the 2A/2B. Tabular data is also provided for a tighter tolerance fit external thread of class 4g6g, which is approximately equivalent to the inch class 3A but with an allowance applied. Formulation and tolerancing data is included for applications requiring other fits.