ISO 965-1和ISO 965-2 有什么区别？

为什么在ISO 4017& ISO 4014中螺纹标准写的是ISO 965-1, 而在螺杆标准DIN 976中螺纹的标准是ISO 965-2?
这两者的螺纹有什么不同？

ISO 965 consists of the following part， under the general title ISO general purpose metric screw threadsTolerances
Part 1: (ISO965-1)Principles and basic data原则和基本数据
Part 2: (ISO965-2)Limits of sizes for general purpose bolt and nut threads - Medium quality一般用途的外螺纹与内螺纹的尺寸限制，中档质量
Part 3: (ISO965-3)Deviations for constructional screw threads结构螺纹的偏差
Part 4: (ISO965-4)Limits of sizes for hot-dip galvanized external threads to mate with internal threads tapped with
tolerance position H or G after galvanizing与由镀锌后公差位置为H或G攻出的内螺纹相匹配的热浸镀锌外螺纹的尺寸限制
Part 5: ((ISO965-5))Limits of sizes for internal screw threads to mate with hot-dip galvanized external screw threads with
maximum size of tolerance position h before galvanizing与镀锌前最大公差位置为H的热浸镀锌外螺纹相匹配的内螺纹的尺寸限制

一个标准，两个不同约束内容

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