本标准规定了MJ profile公制系列螺纹的特性，从ISO 68 M Profile改为在外螺纹根部包括0.18042 P至0.15011 P的强制控制半径，并增加了外螺纹和内螺纹的小直径，以提供0.5625 H的基本螺纹高度，以适应外螺纹最大根部半径。包括以下详细要求: 一个 MJ基本轮廓和设计轮廓 b 公称螺纹直径1.6至200 mm的直径-螺距组合标准系列 c 标准螺纹等级和形状公差 d 螺纹尺寸和公差公式 和 指定MJ线程的方法 f 检验要求 g 航空用螺钉、螺栓、螺母、轴和轴承固定螺纹以及流体配件螺纹尺寸的选定直径-螺距组合表 h MJ螺纹限制尺寸和公差表 我 MJ螺纹尺寸和公差符号

This standard specifies the characteristics of the MJ profile metric series of screw threads, altered from ISO 68 M Profile, to include a mandatory controlled radius of 0.18042P to 0.15011P at the root of the external thread and with the minor diameter of both external and internal threads increased to provide a basic thread height of 0.5625H in order to accommodate the external thread maximum root radius. The following detailed requirements are included: a MJ basic profile and design profiles b Standard series of diameter-pitch combinations for nominal thread diameters from 1.6 to 200 mm c Standard thread classes and form tolerances d Formulae for thread dimensions and tolerances e Method of designating MJ threads f Inspection requirement g Tables for selected diameter-pitch combinations for aerospace screws, bolts, nuts, shaft and bearing retaining screw threads, and fluid fittings thread sizes h Tables for MJ screw threads limiting dimensions and tolerances i Symbols for MJ thread dimensions and tolerances