1、55圆柱内螺纹（RP ） 55圆锥内螺纹（RC ）规 格 钻 孔 直 径 规 格 钻 孔 直 径标准直径 最 大 最 小 标准直径 最 大 最 小1/16 -28 6.5 6.632 6.49 1/16 -28 6.3 6.384 6.2441/8 -28 8.5 8.637 8.495 1/8 -28 8.3 8.388 8.2491/4 -19 11.4 11.549 11.341 1/4 -19 11 11.174 10.9623/8 -19 14.9 15.045 14.846 3/8 -19 14.5 14.658 14.4481/2 -14 18.6 18.773 18.489 1
2、/2 -14 18.1 18.263 17.9793/4 -14 24 24.259 23.975 3/4 -14 23.5 23.663 23.3781 -11 30.2 30.472 30.11 1 -11 29.6 29.822 29.4591 1/4 -11 38.8 39.133 38.7711 1/4 -11 38.2 38.339 37.9761 1/2 -11 44.7 45.026 44.6641 1/2 -11 44 44.232 43.8692 -11 56.5 56.837 56.475 2 -11 55.6 55.844 55.412公制螺纹(M ) 55非密封圆柱内
3、螺纹（G）规 格 钻 孔 直 径 规 格 钻 孔 直 径标准直径 最 大 最 小 标准直径 最 大 最 小M1 0.75 0.785 0.729 1/16 -28 6.7 6.843 6.561M2 1.6 1.679 1.567 1/8 -28 8.7 8.848 8.566M3 2.5 2.599 2.459 1/4 -19 11.7 11.89 11.445M4 3.3 3.422 3.242 3/8 -19 15.2 15.395 14.95M5 4.2 4.334 4.134 1/2 -14 19 19.172 18.631M6 5 5.153 4.917 5/8 -14 21 21
4、.128 20.587M7 6 6.153 5.917 3/4 -14 24.5 24.658 24.117M8 6.8 6.912 6.647 7/8 -14 28.2 28.418 27.877M10 8.5 8.676 8.376 1 -11 30.6 30.931 30.291M12 10.25 10.441 10.106 1 1/8 -11 35.2 35.579 34.939M14 12 12.21 11.835 1 1/4 -11 39.2 39.592 38.952M16 14 14.21 13.835 1 1/2 -11 45 45.485 44.845M18 15.5 15
5、.744 15.294 1 3/4 -11 51 51.428 50.788M20 17.5 17.744 17.294 2 -11 57 57.296 56.656M22 19.5 19.744 19.294M24 21 21.252 20.752 60圆锥内螺纹（NPT）M27 24 24.252 23.752 规 格 钻 孔 直 径M30 26.5 26.771 26.211 标准直径 最 大 最 小M33 29.5 29.771 29.211 1/16 -27 6.135 6.223 6.046M36 32 32.27 31.67 1/8 -27 8.48 8.568 8.393M39
6、 35 35.27 34.67 1/4 -18 10.996 11.128 10.864M42 37.5 37.799 37.129 3/8 -18 14.416 14.548 14.284M45 40.5 40.799 40.129 1/2 -14 17.813 17.983 17.642M48 43 43.297 42.587 3/4 -14 23.127 23.297 22.957M52 47 47.487 46.587 1 -11.5 29.059 29.266 28.851M56 50.5 50.996 50.046 1 1/4 -11.5 37.784 37.991 37.576M64 58 58.505 57.505 1 1/2 -11.5 43.85 44.06 43.646M72 66 66.505 65.505 2 -11.5 55.86 56.07 55.659
