ねじ下穴径表：メートルねじ用
- （）内の数値は、並目ねじは5H(2級)細目ねじは4H・5H(1級)を記載しています。
- ※印はJISより削除されています。
- 太字はメートル並目ねじです。
- D1：JIS 6H(2級)めねじ内径を表します。
- D1は2級相当値を記載しています。
| 単位(mm) | ||||
| 呼び | D1(内径) | ドリル径 （参考） |
||
|---|---|---|---|---|
| Max. | Min. | |||
| M1×0.25 | (0.785) | (0.729) | 0.75 | |
| M1×0.2 | (0.821) | (0.783) | 0.80 | |
| M1.1×0.25 | (0.885) | (0.829) | 0.85 | |
| M1.1×0.2 | (0.921) | (0.883) | 0.90 | |
| M1.2×0.25 | (0.985) | (0.929) | 0.95 | |
| M1.2×0.2 | (1.021) | (0.983) | 1.00 | |
| M1.4×0.3 | (1.142) | (1.075) | 1.10 | |
| M1.4×0.2 | (1.221) | (1.183) | 1.20 | |
| M1.6×0.35 | 1.321 | 1.221 | 1.25 | |
| M1.6×0.2 | (1.421) | (1.383) | 1.40 | |
| ※ | M1.7×0.35 | 1.421 | 1.321 | 1.35 |
| ※ | M1.7×0.2 | 1.521 | 1.483 | 1.45 |
| M1.8×0.35 | 1.521 | 1.421 | 1.45 | |
| M1.8×0.2 | (1.621) | (1.583) | 1.60 | |
| M2×0.4 | 1.679 | 1.567 | 1.60 | |
| M2×0.25 | (1.785) | (1.729) | 1.75 | |
| M2.2×0.45 | 1.838 | 1.713 | 1.75 | |
| M2.2×0.25 | (1.985) | (1.929) | 1.95 | |
| ※ | M2.3×0.4 | 1.979 | 1.867 | 1.90 |
| ※ | M2.3×0.25 | 2.085 | 2.029 | 2.05 |
| M2.5×0.45 | 2.138 | 2.013 | 2.1 | |
| M2.5×0.35 | 2.221 | 2.121 | 2.2 | |
| ※ | M2.6×0.45 | 2.238 | 2.113 | 2.2 |
| ※ | M2.6×0.35 | 2.321 | 2.221 | 2.2 |
| M3×0.5 | 2.599 | 2.459 | 2.5 | |
| M3×0.35 | 2.721 | 2.621 | 2.7 | |
| M3.5×0.6 | 3.010 | 2.850 | 2.9 | |
| M3.5×0.35 | 3.221 | 3.121 | 3.2 | |
| M4×0.7 | 3.422 | 3.242 | 3.3 | |
| M4×0.5 | 3.599 | 3.459 | 3.5 | |
| M4.5×0.75 | 3.878 | 3.688 | 3.8 | |
| M4.5×0.5 | 4.099 | 3.959 | 4.0 | |
| M5×0.8 | 4.334 | 4.134 | 4.2 | |
| M5×0.5 | 4.599 | 4.459 | 4.5 | |
| M5.5×0.5 | 5.099 | 4.959 | 5.0 | |
| M6×1 | 5.153 | 4.917 | 5.0 | |
| ※ | M6×0.75 | 5.378 | 5.188 | 5.3 |
| M6×0.5 | 5.599 | 5.459 | 5.5 | |
| M7×1 | 6.153 | 5.917 | 6.0 | |
| ※ | M7×0.75 | 6.378 | 6.188 | 6.3 |
| M7×0.5 | 6.599 | 6.459 | 6.5 | |
| M8×1.25 | 6.912 | 6.647 | 6.8 | |
| M8×1 | 7.153 | 6.917 | 7.0 | |
| ※ | M8×0.75 | 7.378 | 7.188 | 7.3 |
| M8×0.5 | 7.599 | 7.459 | 7.5 | |
| M9×1.25 | 7.912 | 7.647 | 7.8 | |
| M9×1 | 8.153 | 7.917 | 8.0 | |
| M9×0.75 | 8.378 | 8.188 | 8.3 | |
| M10×1.5 | 8.676 | 8.376 | 8.5 | |
| M10×1.25 | 8.912 | 8.647 | 8.8 | |
| M10×1 | 9.153 | 8.917 | 9.0 | |
| ※ | M10×0.75 | 9.378 | 9.188 | 9.3 |
| M10×0.5 | 9.599 | 9.459 | 9.5 | |
| M11×1.5 | 9.676 | 9.376 | 9.5 | |
| M11×1 | 10.153 | 9.917 | 10.0 | |
| M11×0.75 | 10.378 | 10.188 | 10.3 | |
| M12×1.75 | 10.441 | 10.106 | 10.3 | |
| M12×1.5 | 10.676 | 10.376 | 10.5 | |
| M12×1.25 | 10.912 | 10.647 | 10.8 | |
| ※ | M12×1 | 11.153 | 10.917 | 11.0 |
| M12×0.5 | 11.599 | 11.459 | 11.5 | |
| M14×2 | 12.210 | 11.835 | 12.0 | |
| M14×1.5 | 12.676 | 12.376 | 12.5 | |
| M14×1 | 13.153 | 12.917 | 13.0 | |
| M15×1.5 | 13.676 | 13.376 | 13.5 | |
| M15×1 | 14.153 | 13.917 | 14.0 | |
| M16×2 | 14.210 | 13.835 | 14.0 | |
| M16×1.5 | 14.676 | 14.376 | 14.5 | |
| M16×1 | 15.153 | 14.917 | 15.0 | |
| M17×1.5 | 15.676 | 15.376 | 15.5 | |
| M17×1 | 16.153 | 15.917 | 16.0 | |
| M18×2.5 | 15.744 | 15.294 | 15.5 | |
| M18×2 | 16.210 | 15.835 | 16.0 | |
| M18×1.5 | 16.676 | 16.376 | 16.5 | |
| M18×1 | 17.153 | 16.917 | 17.0 | |
| M20×2.5 | 17.744 | 17.294 | 17.5 | |
| M20×2 | 18.210 | 17.835 | 18.0 | |
| M20×1.5 | 18.676 | 18.376 | 18.5 | |
| M20×1 | 19.153 | 18.917 | 19.0 | |
| M22×2.5 | 19.744 | 19.294 | 19.5 | |
| M22×2 | 20.210 | 19.835 | 20.0 | |
| M22×1.5 | 20.676 | 20.376 | 20.5 | |
| M22×1 | 21.153 | 20.917 | 21.0 | |
| M24×3 | 21.252 | 20.752 | 21.0 | |
| M24×2 | 22.210 | 21.835 | 22.0 | |
| M24×1.5 | 22.676 | 22.376 | 22.5 | |
| M24×1 | 23.153 | 22.917 | 23.0 | |
| M25×2 | 23.210 | 22.835 | 23.0 | |
| M25×1.5 | 23.676 | 23.376 | 23.5 | |
| M25×1 | 24.153 | 23.917 | 24.0 | |
| M26×1.5 | 24.676 | 24.376 | 24.5 | |
| M27×3 | 24.252 | 23.752 | 24.0 | |
| M27×2 | 25.210 | 24.835 | 25.0 | |
| M27×1.5 | 25.676 | 25.376 | 25.5 | |
| M27×1 | 26.153 | 25.917 | 26.0 | |
| M28×2 | 26.210 | 25.835 | 26.0 | |
| M28×1.5 | 26.676 | 26.376 | 26.5 | |
| M28×1 | 27.153 | 26.917 | 27.0 | |
| M30×3.5 | 26.771 | 26.211 | 26.5 | |
| M30×3 | 27.252 | 26.752 | 27.0 | |
| M30×2 | 28.210 | 27.835 | 28.0 | |
| M30×1.5 | 28.676 | 28.376 | 28.5 | |
| M30×1 | 29.153 | 28.917 | 29.0 | |
| M32×2 | 30.210 | 29.835 | 30.0 | |
| M32×1.5 | 30.676 | 30.376 | 30.5 | |
| M33×3.5 | 29.771 | 29.211 | 29.5 | |
| M33×3 | 30.252 | 29.752 | 30.0 | |
| M33×2 | 31.210 | 30.835 | 31.0 | |
| M33×1.5 | 31.676 | 31.376 | 31.5 | |
| M35×1.5 | 33.676 | 33.376 | 33.5 | |
| M36×4 | 32.270 | 31.670 | 32.0 | |
| M36×3 | 33.252 | 32.752 | 33.0 | |
| M36×2 | 34.210 | 33.835 | 34.0 | |
| M36×1.5 | 34.676 | 34.376 | 34.5 | |
| M38×1.5 | 36.676 | 36.376 | 36.5 | |
| M39×4 | 35.270 | 34.670 | 35.0 | |
| M39×3 | 36.252 | 35.752 | 36.0 | |
| M39×2 | 37.210 | 36.835 | 37.0 | |
| M39×1.5 | 37.676 | 37.376 | 37.5 | |
| M40×3 | 37.252 | 36.752 | 37.0 | |
| M40×2 | 38.210 | 37.835 | 38.0 | |
| M40×1.5 | 38.676 | 38.376 | 38.5 | |
| M42×4.5 | 37.799 | 37.129 | 37.5 | |
| M42×4 | 38.270 | 37.670 | 38.0 | |
| M42×3 | 39.252 | 38.752 | 39.0 | |
| M42×2 | 40.210 | 39.835 | 40.0 | |
| M42×1.5 | 40.676 | 40.376 | 40.5 | |
| M45×4.5 | 40.799 | 40.129 | 40.5 | |
| M45×4 | 41.270 | 40.670 | 41.0 | |
| M45×3 | 42.252 | 41.752 | 42.0 | |
| M45×2 | 43.210 | 42.835 | 43.0 | |
| M45×1.5 | 43.676 | 43.376 | 43.5 | |
| M48×5 | 43.297 | 42.587 | 43.0 | |
| M48×4 | 44.270 | 43.670 | 44.0 | |
| M48×3 | 45.252 | 44.752 | 45.0 | |
| M48×2 | 46.210 | 45.835 | 46.0 | |
| M48×1.5 | 46.676 | 46.376 | 46.5 | |
| M50×3 | 47.252 | 46.752 | 47.0 | |
| M50×2 | 48.210 | 47.835 | 48.0 | |
| M50×1.5 | 48.676 | 48.376 | 48.5 | |
