| ねじの呼び | ピッチ (Ｐ) |
下穴 ドリル径 |
２級ねじ下穴径 | ２級めねじ内径 | |
|---|---|---|---|---|---|
| 下穴最小寸法 | 下穴最大寸法 | ||||
| Ｍ 2.5×0.35 | 0.35 | 2.2 | 2.22(75%) | 2.121 | 2.221 |
| Ｍ 3 ×0.35 | 0.35 | 2.7 | 2.72(75%) | 2.621 | 2.721 |
| Ｍ 3.5×0.35 | 0.35 | 3.2 | 3.22(75%) | 3.121 | 3.221 |
| Ｍ 4 ×0.5 | 0.5 | 3.5 | 3.59(75%) | 3.459 | 3.599 |
| Ｍ 4.5×0.5 | 0.5 | 4.0 | 4.09(75%) | 3.959 | 4.099 |
| Ｍ 5 ×0.5 | 0.5 | 4.5 | 4.59(75%) | 4.459 | 4.599 |
| Ｍ 5.5×0.5 | 0.5 | 5.0 | 5.09(75%) | 4.959 | 5.099 |
| Ｍ 6 ×0.75 | 0.75 | 5.3 | 5.35(80%) | 5.188 | 5.378 |
| Ｍ 7 ×0.75 | 0.75 | 6.3 | 6.35(80%) | 6.188 | 6.378 |
| Ｍ 8 ×1 | 1.0 | 7.0 | 7.13(80%) | 6.917 | 7.153 |
| Ｍ 8 ×0.75 | 0.75 | 7.3 | 7.35(80%) | 7.188 | 7.378 |
| Ｍ 9 ×1 | 1.0 | 8.0 | 8.13(80%) | 7.917 | 8.153 |
| Ｍ 9 ×0.75 | 0.75 | 8.3 | 8.35(80%) | 8.188 | 8.378 |
| Ｍ10 ×1.25 | 1.25 | 8.8 | 8.85(85%) | 8.647 | 8.912 |
| Ｍ10 ×1 | 1.0 | 9.0 | 9.13(80%) | 8.917 | 9.153 |
| Ｍ10 ×0.75 | 0.75 | 9.3 | 9.35(80%) | 9.188 | 9.378 |
| Ｍ11 ×1 | 1.0 | 10.0 | 10.13(80%) | 9.917 | 10.153 |
| Ｍ11 ×0.75 | 0.75 | 10.3 | 10.35(80%) | 10.188 | 10.378 |
| Ｍ12 ×1.5 | 1.5 | 10.5 | 10.62(85%) | 10.376 | 10.676 |
| Ｍ12 ×1.25 | 1.25 | 10.8 | 10.85(85%) | 10.647 | 10.912 |
| Ｍ12 ×1 | 1.0 | 11.0 | 11.13(80%) | 10.917 | 11.153 |
| Ｍ14 ×1.5 | 1.5 | 12.5 | 12.62(85%) | 12.376 | 12.676 |
| Ｍ14 ×1 | 1.0 | 13.0 | 13.13(80%) | 12.917 | 13.153 |
| Ｍ15 ×1.5 | 1.5 | 13.5 | 13.62(85%) | 13.376 | 13.676 |
| Ｍ15 ×1 | 1.0 | 14.0 | 14.13(80%) | 13.917 | 14.153 |
| Ｍ16 ×1.5 | 1.5 | 14.5 | 14.62(85%) | 14.376 | 14.676 |
| Ｍ16 ×1 | 1.0 | 15.0 | 15.13(80%) | 14.917 | 15.153 |
| Ｍ17 ×1.5 | 1.5 | 15.5 | 15.62(85%) | 15.376 | 15.676 |
| Ｍ17 ×1 | 1.0 | 16.0 | 16.13(80%) | 15.917 | 16.153 |
| Ｍ18 ×2 | 2.0 | 16.0 | 16.2 (85%) | 15.917 | 16.153 |
| Ｍ18 ×1.5 | 1.5 | 16.0 | 16.62(85%) | 16.376 | 16.676 |
| Ｍ18 ×1 | 1.0 | 17.0 | 17.13(80%) | 16.917 | 17.153 |
| Ｍ20 ×2 | 2.0 | 18.0 | 18.2 (85%) | 17.835 | 18.210 |
| Ｍ20 ×1.5 | 1.5 | 18.5 | 18.62(85%) | 18.376 | 18.676 |
| Ｍ20 ×1 | 1.0 | 19.0 | 19.13(80%) | 18.917 | 19.153 |
| Ｍ22 ×2 | 2.0 | 20.0 | 20.2 (85%) | 19.835 | 20.210 |
| Ｍ22 ×1.5 | 1.5 | 20.5 | 20.62(85%) | 20.376 | 20.676 |
| Ｍ22 ×1 | 1.0 | 21.0 | 21.13(80%) | 20.917 | 21.153 |
| Ｍ24 ×2 | 2.0 | 22.0 | 22.2 (85%) | 21.835 | 22.210 |
| Ｍ24 ×1.5 | 1.5 | 22.5 | 22.62(85%) | 22.376 | 22.676 |
| Ｍ24 ×1 | 1.0 | 23.0 | 23.13(80%) | 22.917 | 23.153 |
| Ｍ25 ×2 | 2.0 | 23.0 | 23.2 (85%) | 22.835 | 23.210 |
| Ｍ25 ×1.5 | 1.5 | 23.5 | 23.62(85%) | 23.376 | 23.676 |
| Ｍ25 ×1 | 1.0 | 24.0 | 24.13(80%) | 23.917 | 24.153 |
| Ｍ26 ×1.5 | 1.5 | 24.5 | 24.62(85%) | 24.376 | 24.676 |
| Ｍ27 ×2 | 2.0 | 25.0 | 25.2 (85%) | 24.835 | 25.210 |
| Ｍ27 ×1.5 | 1.5 | 25.5 | 25.62(85%) | 25.376 | 25.676 |
| Ｍ27 ×1 | 1.0 | 26.0 | 26.13(80%) | 25.917 | 26.153 |
| Ｍ28 ×2 | 2.0 | 26.0 | 26.2 (85%) | 25.835 | 26.210 |
| Ｍ28 ×1.5 | 1.5 | 26.5 | 26.62(85%) | 26.376 | 26.676 |
| Ｍ28 ×1 | 1.0 | 27.0 | 27.13(80%) | 26.917 | 27.153 |
| Ｍ27 ×1.5 | 1.5 | 25.5 | 25.62(85%) | 25.376 | 25.676 |
| 3.0 | 27.0 | 27.2 (85%) | 26.752 | 27.252 | |
| Ｍ30 ×2 | 2.0 | 28.0 | 28.2 (85%) | 27.835 | 28.210 |
| Ｍ30 ×1.5 | 1.5 | 28.5 | 28.62(85%) | 28.376 | 28.676 |
| Ｍ30 ×1 | 1.0 | 29.0 | 29.13(80%) | 28.917 | 29.153 |
※赤い文字で書かれたピッチのものは、なるべく用いない。
※呼び径14mm，ピッチ1.25mm(Ｍ14×1.25)のねじは、内燃機関用点火
プラグのねじに限って用いることができる。