m8螺纹底孔多大 铣床牙的孔与螺丝过孔M1 M2 M3 M4 M5 M6 M7 M8 M9分别打多大啊?

题目：

铣床牙的孔与螺丝过孔M1 M2 M3 M4 M5 M6 M7 M8 M9分别打多大啊?

解答：

先分清是什么制,公制还是美制,是粗牙还是细牙.再确定孔径.螺丝攻牙钻孔径和滚丝径对照表 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 M1.0×0.25 0.75 0.785 0.729 NO.1-64(1.854) 1.55 1.582 1.425 M1.1×0.25 0.85 0.885 0.829 NO.2-56(2.184) 1.80 1.871 1.695 M1.2×0.25 0.95 0.985 0.985 NO.3-48(2.515) 2.10 2.146 1.941 M1.4×0.3 1.10 1.142 1.075 NO.4-40(2.845) 2.30 2.385 2.157 M1.6×0.35 1.25 1.321 1.221 NO.5-40(3.175) 2.60 2.697 2.487 M1.7×0.35 1.35 1.421 1.321 NO.6-32(3.505) 2.80 2.895 2.642 M1.8×0.35 1.45 1.521 1.421 NO8-32(4.166) 3.40 3.53 3.302 M2.0×0.4 1.60 1.679 1.567 NO.10-24(4.826) 3.90 3.962 3.683 M2.2×0.45 1.75 1.838 1.713 NO.12-24(5.486) 4.50 4.597 4.344 M2.3×0.4 1.90 1.979 1.867 1/4-20 5.10 5.257 4.979 M2.5×0.45 2.10 2.138 2.013 5/16-18 6.60 6.731 6.401 M2.6×0.45 2.20 2.238 2.113 3/8-16 8.00 8.153 7.798 M3.0×0.5 2.50 2.599 2.459 7/16-14 9.40 9.55 9.144 M3.0×0.6 2.40 2.440 2.280 1/2-13 10.80 11.023 10.592 M3.5×0.6 2.90 3.010 2.850 9/16-12 12.20 12.446 11.989 M4.0×0.7 3.30 3.422 3.242 5/8-11 13.60 12.868 13.386 M4.0×0.75 3.25 3.326 3.106 3/4-10 16.50 18.840 16.307 M4.5×0.75 3.80 3.878 3.688 7/8-9 19.50 19.761 19.177 M5.0×0.8 4.20 4.334 4.134 1 22.20 22.606 21.971 M5.0×0.9 4.10 4.170 3.930 1-1/8-7 25.00 25.349 24.638 M6.0×1.0 5.00 5.153 4.917 1-1/4-7 28.20 28.524 27.813 M7.0×1.0 6.00 6.153 5.917 1-3/8-6 30.80 31.115 30.353 M8.0×1.25 6.80 6.912 6.647 1-1/2-6 34.00 34.290 33.528 M9.0×1.25 7.80 7.912 7.647 1-3/4-5 39.50 39.827 38.964 M10×1.5 8.50 8.676 8.376 2-4-1/2 45.20 45.593 44.679 M11×1.5 9.50 9.676 9.376 M12×1.75 10.30 10.441 10.106 M14×2.0 12.00 12.210 11.835 M16×2.0 14.00 14.210 13.835 M18×2.5 15.50 15.744 15.294 M20×2.5 17.50 17.744 17.294 M22×2.5 19.50 19.744 19.294 M24×3.0 21.00 21.252 20.752 M27×3.0 24.00 24.252 23.752 M30×3.5 26.50 26.771 26.211 螺丝攻牙钻孔径和滚丝径对照表 公制细螺纹 美制细螺纹 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 M1.0×0.2 0.80 0.821 0.783 NO.0-80(1.524) 1.25 1.305 1.182 M1.1×0.2 0.90 0.921 0.883 NO.1-72(1.854) 1.55 1.612 1.474 M1.2×0.2 1.00 1.021 0.983 NO.2-64(2.184) 1.85 1.912 1.756 M1.4×0.2 1.20 1.221 1.183 NO.3-56(2.515) 2.10 2.197 2.025 M1.6×0.2 1.40 1.421 1.383 NO.4-48(2.845) 2.40 2.458 2.271 M1.7×0.2 1.45 1.500 1.460 NO.5-44(3.175) 2.70 2.740 2.551 M1.8×0.2 1.60 1.621 1.583 NO.6-40(3.505) 2.90 3.022 2.820 M2.0×0.25 1.75 1.785 1.729 NO.8-36(4.166) 3.50 3.606 3.404 M2.2×0.25 1.95 1.985 1.929 NO.10-32(4.826) 4.10 4.165 3.963 M2.3×0.25 2.05 2.061 2.001 NO.12-28(5.846) 4.60 4.724 4.496 M2.5×0.35 2.20 2.221 2.121 1/4-28 5.50 5.588 5.360 M2.6×0.35 2.20 2.246 2.186 5/16-24 6.90 7.035 6.782 M3.0×0.35 2.70 2.721 2.621 3/8-24 8.50 8.636 8.382 M3.5×0.35 3.20 3.221 3.121 7/16-20 9.90 10.033 9.729 M4.0×0.5 3.50 3.599 3.459 1/2-20 11.50 11.607 11.329 M4.5×0.5 4.00 4.099 3.959 9/16-18 12.90 13.081 12.751 M5.0×0.5 4.50 4.599 4.459 5/8-18 14.50 14.681 14.351 M5.5×0.5 5.00 5.099 4.959 3/4-16 17.50 17.678 17.323 M6.0×0.75 5.30 5.378 5.188 7/8-14 20.50 20.675 20.270 M6.0×0.5 5.50 5.550 5.400 1-12 23.20 23.571 23.114 M7.0×0.75 6.30 6.378 6.188 1-1/8-12 26.50 26.746 26.289 M7.0×0.5 6.50 6.550 6.400 1-1/4-12 29.50 29.921 29.464 M8.0×1.0 7.00 7.153 6.917 1-3/8-12 32.80 33.096 32.639 M8.0×0.75 7.30 7.378 7.188 1-1/2-12 36.00 36.271 35.814 M8.0×0.5 7.50 7.520 7.400 M9.0×1.0 8.00 8.153 7.917 M9.0×0.75 8.30 8.378 8.188 M10×1.25 8.80 8.912 8.647 M10×1.0 9.00 9.153 8.917 M10×0.75 9.30 9.378 9.188 M10×0.5 9.50 9.520 9.400 M11×1.0 10.00 10.153 9.917 M11×0.75 10.30 10.378 10.188 M12×1.5 10.50 10.676 10.376 M12×1.25 10.80 10.912 10.647 M12×1.0 11.00 11.153 10.917 M12×0.5 11.50 11.520 11.400 M14×1.5 12.50 12.676 12.376 M14×1.0 13.00 13.153 12.917 M15×1.5 13.50 13.676 13.376 M15×1.0 14.00 14.153 13.917 M16×1.5 14.50 14.676 14.376 M16×1.0 15.00 15.153 14.917 M17×1.5 15.50 15.676 15.376 M17×1.0 16.00 16.153 15.917 M18×2.0 16.00 16.210 15.835 M18×1.5 16.50 16.676 16.376 M18×1.0 17.00 17.153 16.917 M20×2.0 18.00 18.210 17.835 M20×1.5 18.50 18.676 18.376 M20×1.0 19.00 19.153 18.917 M22×2.0 20.00 20.210 19.835 M22×1.5 20.50 20.676 20.376 M22×1.0 21.00 21.153 20.917 M24×2.0 22.00 22.210 21.835 M24×1.5 22.50 22.676 22.376 M24×1.0 23.00 23.153 22.917 M25×2.0 23.00 23.210 22.835 M25×1.5 23.50 23.676 23.376 M25×1.0 24.00 24.153 23.917 M26×1.5 24.50 24.676 24.376 M27×2.0 25.00 25.210 24.835 M27×1.5 25.50 25.676 25.376 M27×1.0 26.00 26.153 25.917 M28×2.0 26.00 26.210 25.835 M28×1.5 26.50 26.676 26.376 M28×1.0 27.00 27.153 26.917 M30×3.0 27.00 27.252 26.752 M30×2.0 28.00 28.210 27.835 M30×1.5 28.50 28.676 28.376 M30×1.0 29.00 29.153 28.917 M32×2.0 30.00 30.210 29.835 M32×1.5 30.50 30.676 30.376 M33×3.0 30.00 30.252 29.752 M33×2.0 31.00 31.210 30.835 M33×1.5 31.50 31.676 31.376 M35×1.5 33.50 33.676 33.376 M36×3.0 33.00 33.252 32.752 M36×2.0 34.00 34.210 33.835 M36×1.5 34.50 34.676 34.376 螺丝攻牙钻孔径和滚丝径对照表 公制挤压丝攻钻孔径 美制挤压丝攻钻孔径 规格 精度等级 规格（UNC） 精度等级 G4-G6 G7-G8 G9 G4-G6 G7-G8 G9 M1.0×0.25 0.86 0.88 － NO.2-56UNC 1.94 － － M1.1×0.25 0.96 0.98 － NO.3-48 2.23 － － M1.2×0.25 1.06 1.08 － NO.4-40 2.50 － － M1.4×0.3 1.24 1.25 － NO.5-40 2.83 － － M1.6×0.35 1.41 1.43 － NO.6-32 3.07 － － M1.7×0.35 1.51 1.53 － NO.8-32 3.73 3.77 － M1.8×0.35 1.61 1.63 － NO.10-24 4.24 4.3 － M2.0×0.4 1.78 1.80 － NO.12-24 4.90 4.96 － M2.2×0.45 1.95 1.98 － 1/4-20 － 5.72 － M2.3×0.4 2.08 2.10 － 5/16-18 － 7.24 － M2.5×0.45 2.25 2.28 － 3/8-16 － 8.74 8.81 M2.6×0.45 2.35 2.38 － 7/16-14 － 10.20 10.30 M3.0×0.5 2.73 2.75 － 1/2-13 － 11.27 11.82 M3.5×0.6 3.17 3.20 － NO.2-64UNF 1.97 － － M4.0×0.7 3.62 3.65 3.69 NO.3-56 2.27 － － M5.0×0.8 4.56 4.60 4.64 NO.4-48 2.56 － － M6.0×1.0 5.45 5.50 5.55 NO.5-44 2.86 － － M7.0×1.0 6.45 6.50 6.55 NO.6-40 3.16 － － M8.0×1.25 7.31 7.38 7.44 NO.8-36 3.78 － － M10×1.5 9.18 9.25 9.32 NO.10-32 4.39 4.43 － M10×1.25 9.31 9.38 9.44 NO.12-28 4.99 5.04 － M12×1.75 11.04 11.12 11.21 1/4-28 5.85 5.90 － M12×1.25 11.31 11.38 11.44 5/16-24 7.36 7.41 － 3/8-24 － 9.00 － 7/16-20 － 10.48 10.54 1/2-20 － 12.07 12.13 美制特细螺纹 英制电器螺纹 规格 标准径 2级牙钻孔径 规格 钻孔径 最大 最小 NO.12-32 4.70 4.826 4.623 A 4.0-4.2 1/4 -32 5.60 5.690 5.486 3BA 5/16 -32 7.10 7.264 7.087 4BA 3.0-3.2 3/8 -32 8.70 8.865 8.661 5BA 2.7-2.8 7/16 -28 10.20 10.338 10.135 6BA 2.4-2.5 1/2 -28 11.80 11.938 11.709 9/16 -24 13.20 13.386 13.132 5/8 -24 14.80 14.986 14.732 3/4 -20 17.80 17.958 17.678 7/8 -20 21.00 21.133 20.853 1 -20 24.00 24.308 24.028 螺丝攻牙钻孔径和滚丝径对照表 英制螺纹 公制螺纹 针车用螺纹 规格(UNEF) 钻孔径 规格 滚丝径 规格 滚丝径 硬材 软材 W 1/8 - 40 2.65 2.60 M3×0.5 2.63-2.60 SM1/8-40 2.735-2.688 W 5/32 - 32 3.25 3.20 M3.0×0.6 2.56-2.53 SM1/8-44 2.769-2.722 W 3/16 - 24 3.75 3.70 M3.5×0.6 3.06-3.03 SM9/64-40 3.128-3.083 W 1/4 - 20 5.10 5.00 M4.0×0.7 3.49-3.45 SM11/64-40 3.855-3.805 W 5/16 - 18 6.60 6.50 M4.0×0.75 3.45-3.41 SM3/16-32 4.205-4.155 W 3/8 - 16 8.00 7.90 M4.5×0.75 3.96-3.92 SM3/16-28 4.143-4.093 W 7/16 - 14 9.40 9.30 M5.0×0.8 4.43-4.38 SM7/32-32 5.003-4.955 W 1/2 - 12 10.70 10.50 M5.0×0.9 4.36-4.31 SM15/64-28 5.325-5.570 W 9/16 - 12 12.30 12.00 M6.0×1.0 5.30-5.25 SM1/4-40 5.890-5.735 W 5/8 - 11 13.70 13.50 M7.0×1.0 6.30-6.25 SM1/4-28 5.721-5.366 W 3/4 - 10 16.70 16.50 M8.0×1.0 7.28-7.23 SM9/32-28 6.508-6.648 W 7/8 - 9 19.50 19.30 M8.0×1.25 7.12-7.07 SM11/32-28 8.092-8.432 W1 - 8 22.40 22.00 SM3/8-28 8.880-8.015 W 1-1/8 - 7 25.00 24.80 SM7/16-28 10.466-10.401 W 1 - 1/4 - 7 28.30 28.00 SM7/16-16 10.037-9.967 SM1/2-20 11.819-11.749 SM9/26-20 13.400-13.425 英制管螺纹 英制管螺纹 美制管螺纹 规格 标准径 钻孔径 规格 标准径 有交牙部之长度（最小）中之毋螺牙内径 标准长度（最小）中之毋螺牙内径 规格 钻孔径 最大 最小 使用绞刀时 不用绞刀时 NPT NPS 使用绞刀时 不用绞刀时 PS 1/16 - 28 6.50 6.632 6.490 PT 1/16 - 28 6.10 6.20 6.244 6.384 1/16 - 27 6.10 6.25 6.35 PS 1/8 - 28 8.50 8.637 8.495 PT 1/8 - 28 8.10 8.20 8.249 8.388 1/8 - 27 8.33 8.43 8.74 PS 1/4 - 19 11.40 11.549 11.341 PT 1/4 - 19 10.70 11.00 10.962 11.174 1/4 - 18 10.72 11.13 11.13 PS 3/8 - 19 15.00 15.054 14.846 PT 3/8 - 19 14.20 14.50 14.448 14.658 3/8 - 18 14.27 14.27 14.68 PS 1/2 - 14 18.50 18.773 18.489 PT 1/2 - 14 17.60 18.00 17.979 18.263 1/2 - 14 17.48 17.86 18.26 PS 3/4 -14 24.00 24.259 23.975 PT 3/4 - 14 23.00 23.50 23.378 23.663 3/4 - 14 22.63 23.01 23.42 PS 1 - 11 30.20 30.471 30.111 PT 1- 11 29.00 29.50 29.459 29.822 1 - 11-1/2 28.58 28.98 29.36 PS 1-1/4 - 11 38.80 39.132 38.772 PT 1-1/4 - 11 37.50 38.00 37.976 38.339 1-1/4-11-1/2 37.31 37.69 38.10 PS 1-1/2 - 11 44.80 45.025 44.665 PT 1-1/2 - 11 43.40 44.00 43.869 44.232 1-1/2-11-1/2 43.66 44.04 44.45 PS 2 - 11 56.50 56.836 56.476 PT 2 - 11 54.90 55.50 55.412 55.844 2 - 11 - 1/2 55.58 55.96 56.36