螺纹孔底尺寸表 普通粗牙螺孔 攻丝前钻孔尺寸 公称尺寸 M5× 0.8 M6× 1 M8× 1.25 M10× 1.5 M12× 1.75 M14× 2 M16× 2 M18× 2.5 M20× 2.5 M24× 3 M27× 3 M30× 3.5 M33× 3.5 M36× 4 M42× 4.5 M48× 5 M52× 5 M56× 5.5 M64× 6 普通细牙螺孔 攻丝前钻孔尺寸 中国(旧) ZG1/8″ ZG1/4″ ZG3/8″ ZG1/2″ ZG3/4″ ZG1″ ZG1 1/4″ ZG1 1/2″ ZG2″ ZG2 1/2″ ZG3″ 底孔d 公称尺寸 底孔d 公称尺寸 底孔d 公称尺寸 底孔d 4.2 5.0 6.8 8.5 10.2 12.0 14.0 15.5 17.5 21.0 24.0 26.5 29.5 32.0 37.5 43.0 47.0 50.5 58.0 M8× 1 M10× 1 M12× 1 M14× 1 M16× 1 M18× 1 M20× 1 M22× 1 M24× 1 M27× 1 M30× 1 7.0 9.0 11.0 13.0 15.0 17.0 19.0 21.0 23.0 26.0 29.0 M12× 1.5 M14× 1.5 M16× 1.5 M18× 1.5 M20× 1.5 M22× 1.5 M24× 1.5 M27× 1.5 M30× 1.5 M33× 1.5 M36× 1.5 M42× 1.5 M48× 1.5 10.5 12.5 14.5 16.5 18.5 20.5 22.5 25.5 28.5 31.5 34.5 40.5 46.5 M20× 2 M22× 2 M24× 2 M27× 2 M30× 2 M33× 2 M36× 2 M42× 2 M48× 2 M52× 2 M30× 3 M33× 3 M36× 3 M42× 3 M48× 3 M52× 3 18.0 20.0 22.0 25.0 28.0 31.0 34.0 40.0 46.0 50.0 27.0 30.0 33.0 39.0 45.0 49.0 圆锥管螺孔 攻丝前钻孔尺寸 公称尺寸 中国(新) 日本 Rc1/8″ PT1/8″ Rc1/4″ PT1/4″ Rc3/8″ PT3/8″ Rc1/2″ PT1/2″ Rc3/4″ PT3/4″ Rc1″ PT1″ 1 Rc1 /4″ PT1 1/4″ Rc1 1/2″ PT1 1/2″ Rc2″ PT2″ 1 Rc2 /2″ PT2 1/2″ Rc3″ PT3″ 锥管 螺纹 55度 圆柱管螺孔 攻丝前钻孔尺寸 底孔d 公称尺寸 8.4 11.0 14.5 18.0 23.5 29.5 38.0 44.0 56.0 72.0 84.0 G1/8″ G1/4″ G3/8″ G1/2″ G3/4″ G1″ G1 1/8″ G1 1/4″ G1 1/2″ G1 3/4″ G2″ G1 1/4″ G2 1/2″ G2 3/4″ G3″ 布锥管螺孔 攻丝前钻孔尺寸 公称尺寸 底孔d 底孔d 中国(旧) 中国(新) 8.6 Z1/8″ NPT1/8″ 8.4 11.7 Z1/4″ NPT1/4″ 11.1 15.2 Z3/8″ NPT3/8″ 14.6 18.8 Z1/2″ NPT1/2″ 18.1 24.3 Z3/4″ NPT3/4″ 23.5 30.5 Z1″ NPT1″ 29.4 1 1 35.2 Z1 /4″ NPT1 /4″ 38.2 39.2 Z1 1/2″ NPT1 1/2″ 44.3 45.1 Z2″ NPT2″ 56.3 51 锥管 56.9 螺纹 60度 62.95 72.45 78.8 85.2 直管 螺纹 55度