Metric
(ISO 4032)
| Thread Designation | Width Across Flats (mm) | Nut Height (mm) | Thread Pitch (mm) |
|---|---|---|---|
| M2 | 4.0 | 1.6 | 0.40 |
| M2.5 | 5.0 | 2.0 | 0.45 |
| M3 | 5.5 | 2.4 | 0.50 |
| M4 | 7.0 | 3.2 | 0.70 |
| M5 | 8.0 | 4.7 | 0.80 |
| M6 | 10.0 | 5.2 | 1.00 |
| M8 | 13.0 | 6.8 | 1.25 |
| M10 | 16.0 | 8.4 | 1.50 |
| M12 | 18.0 | 10.8 | 1.75 |
| M16 | 24.0 | 14.8 | 2.00 |
| M20 | 30.0 | 18.0 | 2.50 |
| M24 | 36.0 | 21.5 | 3.00 |
Imperial
(ANSI/ASME B18.2.2)
| Thread Designation | Width Across Flats (in) | Nut Height (in) | Threads Per Inch (TPI) |
|---|---|---|---|
| #0-80 | 5/32" | 3/64" | 80 |
| #2-56 | 3/16" | 1/16" | 56 |
| #4-40 | 1/4" | 3/32" | 40 |
| #6-32 | 5/16" | 7/64" | 32 |
| #8-32 | 11/32" | 1/8" | 32 |
| #10-24 | 3/8" | 1/8" | 24 |
| 1/4"-20 | 7/16" | 7/32" | 20 |
| 5/16"-18 | 1/2" | 17/64" | 18 |
| 3/8"-16 | 9/16" | 21/64" | 16 |
| 7/16"-14 | 11/16" | 3/8" | 14 |
| 1/2"-13 | 3/4" | 7/16" | 13 |
| 5/8"-11 | 15/16" | 35/64" | 11 |
| 3/4"-10 | 1-1/8" | 41/64" | 10 |
| 1"-8 | 1-1/2" | 55/64" | 8 |