公制粗螺纹美制粗螺纹规格标准径2级牙钻孔径规格(UNC)标准径2级牙钻孔径最大最小最大最小M1.0×0.250.75 0.785 0.729 NO.1-64 1.5821.425M1.1×0.250.85 0.885 0.829 NO.2-56 1.8711.695M1.2×0.250.95 0.985 0.985 NO.3-48 2.1461.941M1.4×0.31.10 1.142 1.075 NO.4-40 2.3852.157M1.6×0.351.25 1.321 1.221 NO.5-40 2.6972.487M1.7×0.351.35 1.421 1.321 NO.6-32 2.8952.642M1.8×0.351.45 1.521 1.421 NO8-32 3.533.302M2.0×0.41.60 1.679 1.567 NO.10-24 3.9623.683M2.2×0.451.75 1.838 1.713 NO.12-24 4.5974.344M2.3×0.41.90 1.979 1.867 1 5.2574.979M2.5×0.452.10 2.138 2.013 5 6.7316.401M2.6×0.452.20 2.238 2.113 3 8.1537.798M3.0×0.52.50 2.599 2.459 7 9.559.144M3.0×0.62.40 2.440 2.280 1 11.02310.592M3.5×0.62.90 3.010 2.850 9 12.44611.989M4.0×0.73.30 3.422 3.242 5 12.86813.386M4.0×0.753.25 3.326 3.106 3 18.840 16.307M4.5×0.753.80 3.878 3.688 7 19.761 19.177M5.0×0.84.20 4.334 4.134 122.20 22.606 21.971M5.0×0.94.10 4.170 3.930 1-1 25.349 24.638M6.0×1.05.00 5.153 4.917 1-1 28.524 27.813M7.0×1.06.00 6.153 5.917 1-3 31.115 30.353M8.0×1.256.80 6.912 6.647 1-1 34.290 33.528M9.0×1.257.80 7.912 7.647 1-3 39.827 38.964M10×1.58.50 8.676 8.376 2-4-1 45.593 44.679M11×1.59.50 9.676 9.376 M12×1.7510.30 10.441 10.106 M14×2.012.00 12.210 11.835 M16×2.014.00 14.210 13.835 M18×2.515.50 15.744 15.294 M20×2.517.50 17.744 17.294 M22×2.519.50 19.744 19.294 M24×3.021.00 21.252 20.752 M27×3.024.00 24.252 23.752 M30×3.526.50 26.771 26.211