Thread geometry - British Standard Whitworth (BSW)
All dimensions in inches unless otherwise stated.
 |
d1 - Minor thread diameter male d2 - Minor thread diameter female d3 - Pitch diameter d4 - Major diameter |
|---|
| Thread | Major diameter | Thread per inch | Pitch diameter | Minor diameter male thread |
|---|---|---|---|---|
| 1/16 | 0.0625 | 60 | 0.0518 | 0.0413 |
| 3/32 | 0.0937 | 48 | 0.0804 | 0.0670 |
| 1/8 | 0.1250 | 40 | 0.1090 | 0.0930 |
| 5/32 | 0.1563 | 32 | 0.1362 | 0.1162 |
| 3/16 | 0.1875 | 24 | 0.1608 | 0.1341 |
| 7/32 | 0.2187 | 24 | 0.1920 | 0.1654 |
| 1/4 | 0.2500 | 20 | 0.2180 | 0.1860 |
| 5/16 | 0.3125 | 18 | 0.2769 | 0.2414 |
| 3/8 | 0.3750 | 16 | 0.3350 | 0.2950 |
| 7/16 | 0.4375 | 14 | 0.3918 | 0.3460 |
| Thread | Major diameter | Thread per inch | Pitch diameter | Minor diameter male thread |
|---|---|---|---|---|
| 1/2 | 0.5000 | 12 | 0.4467 | 0.3933 |
| 9/16 | 0.5626 | 12 | 0.5091 | 0.4559 |
| 5/8 | 0.6250 | 11 | 0.5668 | 0.5086 |
| 3/4 | 0.7500 | 10 | 0.6860 | 0.6220 |
| 7/8 | 0.8750 | 9 | 0.8039 | 0.7327 |
| 1 | 1.0000 | 8 | 0.9200 | 0.8400 |
| 1 1/8 | 1.1250 | 7 | 1.0336 | 0.9421 |
| 1 1/4 | 1.2500 | 7 | 1.1586 | 1.0671 |
| 1 3/8 | 1.3750 | 6 | 1.2683 | 1.1616 |
| 1 1/2 | 1.5000 | 6 | 1.3933 | 1.2866 |
| Thread | Major diameter | Thread per inch | Pitch diameter | Minor diameter male thread |
|---|---|---|---|---|
| 1 5/8 | 1.6251 | 5 | 1.4970 | 1.3689 |
| 1 3/4 | 1.7501 | 5 | 1.6220 | 1.4939 |
| 1 7/8 | 1.8751 | 4.5 | 1.7328 | 1.5905 |
| 2 | 2.0001 | 4.5 | 1.8578 | 1.7155 |
| 2 1/4 | 2.2501 | 4 | 2.0900 | 1.9299 |
| 2 1/2 | 2.5001 | 4 | 2.3400 | 2.1799 |
| 2 3/4 | 2.7501 | 3.5 | 2.5671 | 2.3842 |
| 3 | 3.0001 | 3.5 | 2.8172 | 2.6342 |
| 3 1/4 | 3.2501 | 3.25 | 3.0531 | 2.8561 |
| 3 1/2 | 3.5001 | 3.25 | 3.3031 | 3.1061 |
| Thread | Major diameter | Thread per inch | Pitch diameter | Minor diameter male thread |
|---|---|---|---|---|
| 3 3/4 | 3.7502 | 3 | 3.5367 | 3.3232 |
| 4 | 4.0002 | 3 | 3.7867 | 3.5732 |
| 4 1/4 | 4.2502 | 2.875 | 4.0274 | 3.8047 |
| 4 1/2 | 4.5002 | 2.875 | 4.2774 | 4.0547 |
| 4 3/4 | 4.7506 | 2.75 | 4.5173 | 4.2766 |
| 5 | 5.0002 | 2.75 | 4.7673 | 4.5345 |
| 5 1/4 | 5.2502 | 2.625 | 5.0063 | 4.7623 |
| 5 1/2 | 5.5002 | 2.625 | 5.2563 | 5.0123 |
| 5 3/4 | 5.7502 | 2.5 | 5.4941 | 5.2379 |
| 6 | 6.0002 | 2.5 | 5.7441 | 5.4880 |