# Engineering Tables/Metric Threads

| Nominal Diameter (mm) | Choice | Thread Pitch | Series | Tapping Drill (mm) | Clearance Drills (mm) | Clearance Drills (mm) |
| Nominal Diameter (mm) | Choice | Thread Pitch | Series | Tapping Drill (mm) | Tight Fit | Free Fit |
| 1 | 1st | 0.20 | Fine | 0.80 | 1.05 | 1.20 |
| 1 | 1st | 0.25 | Coarse | 0.75 | 1.05 | 1.20 |
| 1.1 | 2nd | 0.20 | Fine | 0.90 | 1.15 | 1.30 |
| 1.1 | 2nd | 0.25 | Coarse | 0.85 | 1.15 | 1.30 |
| 1.2 | 1st | 0.20 | Fine | 1.00 | 1.30 | 1.50 |
| 1.2 | 1st | 0.25 | Coarse | 0.95 | 1.30 | 1.50 |
| 1.4 | 2nd | 0.20 | Fine | 1.20 | 1.50 | 1.70 |
| 1.4 | 2nd | 0.30 | Coarse | 1.10 | 1.50 | 1.70 |
| 1.6 | 1st | 0.20 | Fine | 1.40 | 1.70 | 2.00 |
| 1.6 | 1st | 0.35 | Coarse | 1.25 | 1.70 | 2.00 |
| 1.8 | 2nd | 0.20 | Fine | 1.60 | 1.90 | 2.20 |
| 1.8 | 2nd | 0.35 | Coarse | 1.45 | 1.90 | 2.20 |
| 2 | 1st | 0.25 | Fine | 1.75 | 2.20 | 2.60 |
| 2 | 1st | 0.40 | Coarse | 1.60 | 2.20 | 2.60 |
| 2.2 | 2nd | 0.25 | Fine | 1.95 | 2.40 | 2.80 |
| 2.2 | 2nd | 0.45 | Coarse | 1.75 | 2.40 | 2.80 |
| 2.5 | 1st | 0.25 | Fine | 2.15 | 2.70 | 3.10 |
| 2.5 | 1st | 0.45 | Coarse | 2.05 | 2.70 | 3.10 |
| 3 | 1st | 0.35 | Fine | 2.65 | 3.20 | 3.60 |
| 3 | 1st | 0.50 | Coarse | 2.50 | 3.20 | 3.60 |
| 3.5 | 2nd | 0.35 | Fine | 3.15 | 3.70 | 4.20 |
| 3.5 | 2nd | 0.60 | Coarse | 2.90 | 3.70 | 4.20 |
| 4 | 1st | 0.50 | Fine | 3.50 | 4.30 | 4.80 |
| 4 | 1st | 0.70 | Coarse | 3.30 | 4.30 | 4.80 |
| 4.5 | 2nd | 0.50 | Fine | 4.00 | 4.80 | 5.30 |
| 4.5 | 2nd | 0.75 | Coarse | 3.70 | 4.80 | 5.30 |
| 5 | 1st | 0.50 | Fine | 4.50 | 5.30 | 5.80 |
| 5 | 1st | 0.80 | Coarse | 4.20 | 5.30 | 5.80 |
| 5.5 | 3rd | 0.50 | Fine | 5.00 | 5.80 | 6.40 |
| 6 | 1st | 0.75 | Fine | 5.25 | 6.40 | 7.00 |
| 6 | 1st | 1.00 | Coarse | 5.00 | 6.40 | 7.00 |
| 7 | 2nd | 0.75 | Fine | 6.25 | 7.40 | 8.00 |
| 7 | 2nd | 1.00 | Coarse | 6.00 | 7.40 | 8.00 |
| 8 | 1st | 0.75 | Fine | 7.25 | 8.40 | 10.00 |
| 8 | 1st | 1.00 | Fine | 7.50 | 8.40 | 10.00 |
| 8 | 1st | 1.25 | Coarse | 6.80 | 8.40 | 10.00 |
| 9 | 3rd | 0.75 | Fine | 8.25 | 9.50 | 10.50 |
| 9 | 3rd | 1.00 | Fine | 8.00 | 9.50 | 10.50 |
| 9 | 3rd | 1.25 | Coarse | 7.80 | 9.50 | 10.50 |
| 10 | 1st | 0.75 | Fine | 9.25 | 10.50 | 12.00 |
| 10 | 1st | 1.00 | Fine | 9.00 | 10.50 | 12.00 |
| 10 | 1st | 1.25 | Fine | 8.80 | 10.50 | 12.00 |
| 10 | 1st | 1.50 | Coarse | 8.50 | 10.50 | 12.00 |
| 11 | 3rd | 0.75 | Fine | 10.25 | 12.00 | 13.00 |
| 11 | 3rd | 1.00 | Fine | 10.00 | 12.00 | 13.00 |
| 11 | 3rd | 1.50 | Coarse | 9.50 | 12.00 | 13.00 |
| 12 | 1st | 1.00 | Fine | 11.00 | 13.00 | 15.00 |
| 12 | 1st | 1.25 | Fine | 10.75 | 13.00 | 15.00 |
| 12 | 1st | 1.50 | Fine | 10.50 | 13.00 | 15.00 |
| 12 | 1st | 2.00 | Coarse | 10.20 | 13.00 | 15.00 |
| 14 | 2nd | 1.00 | Fine | 13.00 | 15.00 | 17.00 |
| 14 | 2nd | 1.25 | Fine | 12.80 | 15.00 | 17.00 |
| 14 | 2nd | 1.50 | Fine | 12.50 | 15.00 | 17.00 |
| 14 | 2nd | 2.00 | Coarse | 12.00 | 15.00 | 17.00 |
| 15 | 3rd | 1.00 | Fine | 14.00 | 16.00 | 18.00 |
| 15 | 3rd | 1.50 | Fine | 13.50 | 16.00 | 18.00 |
| 16 | 1st | 1.00 | Fine | 15.00 | 17.00 | 19.00 |
| 16 | 1st | 1.50 | Fine | 14.50 | 17.00 | 19.00 |
| 16 | 1st | 2.00 | Coarse | 14.00 | 17.00 | 19.00 |
| 17 | 3rd | 1.00 | Fine | 16.00 | 18.00 | 20.00 |
| 17 | 3rd | 1.50 | Fine | 15.50 | 18.00 | 20.00 |
| 18 | 2nd | 1.00 | Fine | 17.00 | 19.00 | 21.00 |
| 18 | 2nd | 1.50 | Fine | 16.50 | 19.00 | 21.00 |
| 18 | 2nd | 2.00 | Fine | 16.00 | 19.00 | 21.00 |
| 18 | 2nd | 2.50 | Coarse | 15.50 | 19.00 | 21.00 |
| 20 | 1st | 1.00 | Fine | 19.00 | 21.00 | 24.00 |
| 20 | 1st | 1.50 | Fine | 18.50 | 21.00 | 24.00 |
| 20 | 1st | 2.00 | Fine | 18.00 | 21.00 | 24.00 |
| 20 | 1st | 2.50 | Coarse | 17.50 | 21.00 | 24.00 |
| 22 | 2nd | 1.00 | Fine | 21.00 | 23.00 | 26.00 |
| 22 | 2nd | 1.50 | Fine | 20.50 | 23.00 | 26.00 |
| 22 | 2nd | 2.00 | Fine | 20.00 | 23.00 | 26.00 |
| 22 | 2nd | 2.50 | Coarse | 19.50 | 23.00 | 26.00 |
| 24 | 1st | 1.00 | Fine | 23.00 | 25.00 | 28.00 |
| 24 | 1st | 1.50 | Fine | 22.50 | 25.00 | 28.00 |
| 24 | 1st | 2.00 | Fine | 22.00 | 25.00 | 28.00 |
| 24 | 1st | 3.00 | Coarse | 21.00 | 25.00 | 28.00 |
| 25 | 3rd | 1.00 | Fine | 24.00 | 26.00 | 30.00 |
| 25 | 3rd | 1.50 | Fine | 23.50 | 26.00 | 30.00 |
| 25 | 3rd | 2.00 | Fine | 23.00 | 26.00 | 30.00 |
| 26 | 3rd | 1.00 | Fine | 24.50 | 27.00 | 31.00 |
| 27 | 2nd | 1.00 | Fine | 26.00 | 28.00 | 32.00 |
| 27 | 2nd | 1.50 | Fine | 25.50 | 28.00 | 32.00 |
| 27 | 2nd | 2.00 | Fine | 25.00 | 28.00 | 32.00 |
| 27 | 2nd | 3.00 | Coarse | 24.00 | 28.00 | 32.00 |
| 28 | 3rd | 1.00 | Fine | 27.00 | XX.00 | XX.00 |
| 28 | 3rd | 1.50 | Fine | 26.50 | XX.00 | XX.00 |
| 28 | 3rd | 2.00 | Fine | 26.00 | XX.00 | XX.00 |
| 30 | 1st | 1.00 | Fine | 29.00 | 31.00 | 35.00 |
| 30 | 1st | 1.50 | Fine | 28.50 | 31.00 | 35.00 |
| 30 | 1st | 2.00 | Fine | 28.00 | 31.00 | 35.00 |
| 30 | 1st | 3.00 | Fine | 27.00 | 31.00 | 35.00 |
| 30 | 1st | 3.50 | Coarse | 26.50 | 31.00 | 35.00 |
| 32 | 3rd | 1.50 | Fine | 30.50 | XX.00 | XX.00 |
| 32 | 3rd | 2.00 | Fine | 30.00 | XX.00 | XX.00 |
| 33 | 2nd | 1.50 | Fine | 31.50 | 34.00 | 38.00 |
| 33 | 2nd | 2.00 | Fine | 31.00 | 34.00 | 38.00 |
| 33 | 2nd | 3.00 | Fine | 30.00 | 34.00 | 38.00 |
| 33 | 2nd | 3.50 | Coarse | 29.50 | 34.00 | 38.00 |
| 35 | 3rd | 1.50 | Fine | 33.50 | XX.00 | XX.00 |
| 35 | 3rd | 2.00 | Fine | 33.00 | XX.00 | XX.00 |
| 36 | 1st | 1.50 | Fine | 34.50 | 37.00 | 42.00 |
| 36 | 1st | 2.00 | Fine | 34.00 | 37.00 | 42.00 |
| 36 | 1st | 3.00 | Fine | 33.00 | 37.00 | 42.00 |
| 36 | 1st | 4.00 | Coarse | 32.00 | 37.00 | 42.00 |
| 38 | 3rd | 1.50 | Fine | XX.50 | | |
| 39 | 2nd | 1.50 | Fine | 37.50 | 40.00 | 45.00 |
| 39 | 2nd | 2.00 | Fine | 37.00 | 40.00 | 45.00 |
| 39 | 2nd | 3.00 | Fine | 36.00 | 40.00 | 45.00 |
| 39 | 2nd | 4.00 | Coarse | 35.50 | 40.00 | 45.00 |
| 40 | 3rd | 1.50 | Fine | 38.50 | | |
| 40 | 3rd | 2.00 | Fine | 38.00 | | |
| 40 | 3rd | 3.00 | Fine | 37.00 | | |
| 42 | 1st | 1.50 | Fine | 40.50 | 43.00 | 48.00 |
| 42 | 1st | 2.00 | Fine | 40.00 | 43.00 | 48.00 |
| 42 | 1st | 3.00 | Fine | 39.00 | 43.00 | 48.00 |
| 42 | 1st | 4.00 | Fine | 38.00 | 43.00 | 48.00 |
| 42 | 1st | 4.50 | Coarse | 37.50 | 43.00 | 48.00 |
| 45 | 2nd | 1.50 | Fine | 43.50 | 46.00 | 52.00 |
| 45 | 2nd | 2.00 | Fine | 43.00 | 46.00 | 52.00 |
| 45 | 2nd | 3.00 | Fine | 42.00 | 46.00 | 52.00 |
| 45 | 2nd | 4.00 | Fine | 41.00 | 46.00 | 52.00 |
| 45 | 2nd | 4.50 | Coarse | 40.50 | 46.00 | 52.00 |
| 48 | 1st | 1.50 | Fine | 46.50 | 50.00 | 56.00 |
| 48 | 1st | 2.00 | Fine | 46.00 | 50.00 | 56.00 |
| 48 | 1st | 3.00 | Fine | 45.00 | 50.00 | 56.00 |
| 48 | 1st | 4.00 | Fine | 44.00 | 50.00 | 56.00 |
| 48 | 1st | 5.00 | Coarse | 43.00 | 50.00 | 56.00 |
| 50 | 3rd | 1.50 | Fine | 48.50 | | |
| 50 | 3rd | 2.00 | Fine | 48.00 | | |
| 50 | 3rd | 3.00 | Fine | 47.00 | | |
| 52 | 2nd | 1.50 | Fine | 50.50 | 54.00 | 62.00 |
| 52 | 2nd | 2.00 | Fine | 50.00 | 54.00 | 62.00 |
| 52 | 2nd | 3.00 | Fine | 49.00 | 54.00 | 62.00 |
| 52 | 2nd | 4.00 | Fine | 48.00 | 54.00 | 62.00 |
| 52 | 2nd | 5.00 | Coarse | 47.00 | 54.00 | 62.00 |
| 55 | 3rd | 1.50 | Fine | 53.50 | | |
| 55 | 3rd | 2.00 | Fine | 53.00 | | |
| 55 | 3rd | 3.00 | Fine | 52.00 | | |
| 55 | 3rd | 4.00 | Fine | 51.00 | | |
| 56 | 1st | 1.50 | Fine | 54.50 | 58.00 | 66.00 |
| 56 | 1st | 2.00 | Fine | 54.00 | 58.00 | 66.00 |
| 56 | 1st | 3.00 | Fine | 53.00 | 58.00 | 66.00 |
| 56 | 1st | 4.00 | Fine | 52.00 | 58.00 | 66.00 |
| 56 | 1st | 5.50 | Coarse | 50.50 | 58.00 | 66.00 |
| Notes: | Nominal diameters, pitches, series and choices as specified in ISO 261. The Coarse Series is the preferred series. The Fine Series is to be used only when the Coarse Series is not suitable due to wall thickness or other space considerations. | Nominal diameters, pitches, series and choices as specified in ISO 261. The Coarse Series is the preferred series. The Fine Series is to be used only when the Coarse Series is not suitable due to wall thickness or other space considerations. | Nominal diameters, pitches, series and choices as specified in ISO 261. The Coarse Series is the preferred series. The Fine Series is to be used only when the Coarse Series is not suitable due to wall thickness or other space considerations. | Nominal diameters, pitches, series and choices as specified in ISO 261. The Coarse Series is the preferred series. The Fine Series is to be used only when the Coarse Series is not suitable due to wall thickness or other space considerations. | Nominal diameters, pitches, series and choices as specified in ISO 261. The Coarse Series is the preferred series. The Fine Series is to be used only when the Coarse Series is not suitable due to wall thickness or other space considerations. | Nominal diameters, pitches, series and choices as specified in ISO 261. The Coarse Series is the preferred series. The Fine Series is to be used only when the Coarse Series is not suitable due to wall thickness or other space considerations. |