Thread chart
Pitch, tap-drill size and major/minor diameter for metric coarse and fine threads (M1–M48) plus UNC and UNF. Filter by thread name, e.g. M10 or 1/4-20.
Metric coarse (M)
| Thread | Pitch | Tap drill | Major Ø | Minor Ø |
|---|---|---|---|---|
| M1 | 0.25 | 0.75 | 1.000 | 0.693 |
| M1.2 | 0.25 | 0.95 | 1.200 | 0.893 |
| M1.4 | 0.30 | 1.10 | 1.400 | 1.032 |
| M1.6 | 0.35 | 1.25 | 1.600 | 1.170 |
| M1.8 | 0.35 | 1.45 | 1.800 | 1.370 |
| M2 | 0.40 | 1.60 | 2.000 | 1.509 |
| M2.5 | 0.45 | 2.05 | 2.500 | 1.948 |
| M3 | 0.50 | 2.50 | 3.000 | 2.387 |
| M3.5 | 0.60 | 2.90 | 3.500 | 2.764 |
| M4 | 0.70 | 3.30 | 4.000 | 3.141 |
| M5 | 0.80 | 4.20 | 5.000 | 4.019 |
| M6 | 1.00 | 5.00 | 6.000 | 4.773 |
| M7 | 1.00 | 6.00 | 7.000 | 5.773 |
| M8 | 1.25 | 6.80 | 8.000 | 6.466 |
| M10 | 1.50 | 8.50 | 10.000 | 8.160 |
| M12 | 1.75 | 10.20 | 12.000 | 9.853 |
| M14 | 2.00 | 12.00 | 14.000 | 11.546 |
| M16 | 2.00 | 14.00 | 16.000 | 13.546 |
| M18 | 2.50 | 15.50 | 18.000 | 14.933 |
| M20 | 2.50 | 17.50 | 20.000 | 16.933 |
| M22 | 2.50 | 19.50 | 22.000 | 18.933 |
| M24 | 3.00 | 21.00 | 24.000 | 20.320 |
| M27 | 3.00 | 24.00 | 27.000 | 23.320 |
| M30 | 3.50 | 26.50 | 30.000 | 25.706 |
| M33 | 3.50 | 29.50 | 33.000 | 28.706 |
| M36 | 4.00 | 32.00 | 36.000 | 31.093 |
| M39 | 4.00 | 35.00 | 39.000 | 34.093 |
| M42 | 4.50 | 37.50 | 42.000 | 36.479 |
| M45 | 4.50 | 40.50 | 45.000 | 39.479 |
| M48 | 5.00 | 43.00 | 48.000 | 41.866 |
Metric fine
| Thread | Pitch | Tap drill | Major Ø | Minor Ø |
|---|---|---|---|---|
| M6×0.75 | 0.75 | 5.25 | 6.000 | 5.080 |
| M8×1.0 | 1.00 | 7.00 | 8.000 | 6.773 |
| M10×1.0 | 1.00 | 9.00 | 10.000 | 8.773 |
| M10×1.25 | 1.25 | 8.75 | 10.000 | 8.466 |
| M12×1.0 | 1.00 | 11.00 | 12.000 | 10.773 |
| M12×1.25 | 1.25 | 10.75 | 12.000 | 10.466 |
| M12×1.5 | 1.50 | 10.50 | 12.000 | 10.160 |
| M14×1.5 | 1.50 | 12.50 | 14.000 | 12.160 |
| M16×1.5 | 1.50 | 14.50 | 16.000 | 14.160 |
| M18×1.5 | 1.50 | 16.50 | 18.000 | 16.160 |
| M20×1.5 | 1.50 | 18.50 | 20.000 | 18.160 |
| M24×2.0 | 2.00 | 22.00 | 24.000 | 21.546 |
UNC (unified coarse)
| Thread | Pitch | Tap drill | Major Ø | Minor Ø |
|---|---|---|---|---|
| #4-40 | 0.635 | 2.26 | 2.845 | 2.156 |
| #6-32 | 0.794 | 2.80 | 3.505 | 2.642 |
| #8-32 | 0.794 | 3.45 | 4.166 | 3.302 |
| #10-24 | 1.058 | 3.90 | 4.826 | 3.683 |
| 1/4-20 | 1.270 | 5.10 | 6.350 | 4.978 |
| 5/16-18 | 1.411 | 6.50 | 7.938 | 6.401 |
| 3/8-16 | 1.588 | 7.90 | 9.525 | 7.849 |
| 7/16-14 | 1.814 | 9.20 | 11.113 | 9.195 |
| 1/2-13 | 1.954 | 10.50 | 12.700 | 10.592 |
| 9/16-12 | 2.117 | 12.00 | 14.288 | 11.989 |
| 5/8-11 | 2.309 | 13.50 | 15.875 | 13.376 |
| 3/4-10 | 2.540 | 16.25 | 19.050 | 16.299 |
| 7/8-9 | 2.822 | 19.25 | 22.225 | 19.177 |
| 1-8 | 3.175 | 22.25 | 25.400 | 22.022 |
UNF (unified fine)
| Thread | Pitch | Tap drill | Major Ø | Minor Ø |
|---|---|---|---|---|
| #4-48 | 0.529 | 2.40 | 2.845 | 2.271 |
| #6-40 | 0.635 | 2.95 | 3.505 | 2.819 |
| #8-36 | 0.706 | 3.50 | 4.166 | 3.403 |
| #10-32 | 0.794 | 4.10 | 4.826 | 3.962 |
| 1/4-28 | 0.907 | 5.50 | 6.350 | 5.367 |
| 5/16-24 | 1.058 | 6.90 | 7.938 | 6.792 |
| 3/8-24 | 1.058 | 8.50 | 9.525 | 8.379 |
| 7/16-20 | 1.270 | 9.90 | 11.113 | 9.741 |
| 1/2-20 | 1.270 | 11.50 | 12.700 | 11.328 |
| 9/16-18 | 1.411 | 12.90 | 14.288 | 12.750 |
| 5/8-18 | 1.411 | 14.50 | 15.875 | 14.338 |
| 3/4-16 | 1.588 | 17.50 | 19.050 | 17.399 |
| 7/8-14 | 1.814 | 20.50 | 22.225 | 20.421 |
| 1-12 | 2.117 | 23.25 | 25.400 | 23.364 |
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