外螺纹外径公差对照表外径尺寸范围 外径尺寸平均值 锥管螺纹 M8x1 φ7.884 M10x1 φ9.884 M10x1.5 φ9.85 M12x0.75 (φ11.925) 直管螺纹 M12x1.25 φ11.867 M12x1.5 φ11.85 M14x1 φ13.884 M14x1.5 φ13.85 M16x1 φ15.884 M16x1.25 φ15.886 M16x1.5 φ15.85 M18x1 φ17.884 M18x1.5 φ17.85 M20x1 φ19.884 特殊螺纹 M20x1.5 φ19.853 7/16-20uNF φ11.112 M22x1 φ21.884 M22x1.5 M24x1 φ23.884 M25x1 φ24.884 M25x1.5 φ24.85 M26x1 147′24″ M26x1.5 M27x1 φ26.884 M27x1.5 φ26.85 M27x2 φ26.822 M30x1.5 φ29.85 M30x2 φ29.80 M36x2 φ35.822 M40x2 φ39.822 M48x1.5 φ47.85 M50x1.5 φ49.85 M70x1.5 φ69.85 公称直径x螺距 φ7.794~7.974 R1/8 L=6.5时φ9.728 φ9.794~9.974 R1/4 L=9.7时φ13.157 φ9.732~9.968 R1/2 L=13.2时φ20.955 (φ11.87~11.98) φ11.76~11.974 G1/16(28扣) φ7.509~7.723 φ11.732~11.968 G1/8(28扣) φ9.50~9.729 φ13.794~13.974 G1/4(19扣) φ12.907~13.158 φ13.732~13.968 G1/2(14扣) φ20.671~20.955 φ15.794~15.974 G3/4(14扣) φ26.157~26.44 φ15.76~15.972 G1 (11扣) φ32.889~33.25 φ15.732~15.968 G11/2 (11扣)φ47.40~47.805 φ17.794~17.974 φ17.732~17.968 φ19.794~19.974 φ19.732~19.974 φ21.794~21.974 5/8-18uNF φ14.96~15.387 3/4-16uNF φ18.72~19.05 φ23.794~23.974 φ24.794~24.974 φ24.732~24.968 NPT1/4 L=9.5时 最大φ13.572 φ26.794~26.974 PG7(20扣)大径φ12.5小径φ11.28 φ26.732~26.968 φ26.682~26.962 φ29.732~29.968 φ29.628~29.962 φ35.682~35.962 φ39.682~39.962 φ47.732~47.962 φ49.732~49.962 φ69.632~69.968 公式= 外径-0.1P(-0.1) 内螺纹小径公差对照表 小径尺寸范围 小径尺寸平均值 M8x1.25 φ6.78 M12x0.75 φ11.279 M12x1 φ11.036 M12x1.25 φ10.781 M12x1.5 φ10.523 M14x1.5 φ12.527 M16x0.75 φ15.283 M18x0.75 φ17.283 M18x1.5 φ16.526 M20x1 φ19.037 M20x1.5 φ18.523 M24x1 φ23.037 M26x1 φ25.037 M27x1 φ25.037 M27x1.5 φ25.523 M27x2 φ25.023 M28x1 φ27.037 M30x1 φ29.037 M30x1.5 φ28.523 M30x2 φ28.023 M32x1.5 φ30.523 M38x2 φ36.023 M40x2 φ38.023 M42x2 φ40.023 M48x1 φ47.037 M48x1.5 φ46.523 M50x1.5 φ48.523 M68x2 φ66.023 φ11.69 φ30.60 φ8.766 公称直径x螺距 平均值公式=公称直径-螺距 φ6.649~6.912 φ11.18~11.378 φ10.918~11.153 φ10.649~10.912 例:M12-1.25=10.75平均值 φ10.377~10.676 或M12-1.25x1.0825=10.648最小值 φ12.377~12.676 φ15.188~15.378 φ17.188~17.378 φ16.376~16.676 φ18.92~19.154 φ18.376~18.676 φ22.92~23.154 φ24.92~25.154 φ25.92~26.154 φ25.376~25.676 φ24.835~25.21 φ26.92~27.154 φ28.92~29.154 φ28.376~28.676 φ27.835~28.21 φ30.376~30.676 φ35.835~36.21 φ37.835~38.21 φ39.835~40.21 φ46.92~47.154 φ46.376~46.676 φ48.376~48.676 φ65.835~66.21 G1/4(19扣) φ11.56~11.83 G1(11扣) φ30.43~30.78 NPT1/8(27扣)