Whitworth Threads
British Standard Whitworth fastener thread BS84 1956
Bolts, nuts, screws and fastenings with BSW threads
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| BSW | Nominal | TPI Threads per inch | PITCH | Major Diameter | Pitch Diameter | Minor Diameter male thread | Thread Height female thread | Tap Drill |
| P | d=D | d2=D2 | d3 | H1 | ||||
| 1/16" | 0.063 | 60 | 0.0167 | 0.0625 | 0.0518 | 0.0413 | 0.0106 | 0.0453 |
| 3/32" | 0.094 | 48 | 0.0208 | 0.0937 | 0.0804 | 0.0670 | 0.0133 | 0.0748 |
| 1/8" | 0.125 | 40 | 0.0250 | 0.1250 | 0.1090 | 0.0930 | 0.0160 | 0.0984 |
| 5/32" | 0.156 | 32 | 0.0312 | 0.1563 | 0.1362 | 0.1162 | 0.0200 | 0.1260 |
| 3/16" | 0.188 | 24 | 0.0417 | 0.1875 | 0.1608 | 0.1341 | 0.0267 | 0.1457 |
| 7/32" | 0.219 | 24 | 0.0417 | 0.2187 | 0.1920 | 0.1654 | 0.0267 | 0.1772 |
| 1/4" | 0.250 | 20 | 0.0500 | 0.2500 | 0.2180 | 0.1860 | 0.0320 | 0.2008 |
| 5/16" | 0.313 | 18 | 0.0556 | 0.3125 | 0.2769 | 0.2414 | 0.0356 | 0.2559 |
| 3/8" | 0.375 | 16 | 0.0625 | 0.3750 | 0.3350 | 0.2950 | 0.0400 | 0.3110 |
| 7/16" | 0.438 | 14 | 0.0714 | 0.4375 | 0.3918 | 0.3460 | 0.0457 | 0.3622 |
| 1/2" | 0.500 | 12 | 0.0833 | 0.5000 | 0.4467 | 0.3933 | 0.0533 | 0.4094 |
| 9/16" | 0.563 | 12 | 0.0833 | 0.5626 | 0.5091 | 0.4559 | 0.0533 | 0.4681 |
| 5/8" | 0.625 | 11 | 0.0909 | 0.6250 | 0.5668 | 0.5086 | 0.0582 | 0.5276 |
| 3/4" | 0.750 | 10 | 0.1000 | 0.7500 | 0.6860 | 0.6220 | 0.0641 | 0.6398 |
| 7/8" | 0.875 | 9 | 0.1111 | 0.8750 | 0.8039 | 0.7327 | 0.0711 | 0.7579 |
| 1" | 1.000 | 8 | 0.1250 | 1.0000 | 0.9200 | 0.8400 | 0.0800 | 0.8661 |
| 1 1/8" | 1.125 | 7 | 0.1429 | 1.1250 | 1.0336 | 0.9421 | 0.0915 | 0.9646 |
| 1 1/4" | 1.250 | 7 | 0.1429 | 1.2500 | 1.1586 | 1.0671 | 0.0915 | 1.0728 |
| 1 3/8" | 1.375 | 6 | 0.1667 | 1.3750 | 1.2683 | 1.1616 | 0.1067 | 1.1909 |
| 1 1/2" | 1.500 | 6 | 0.1667 | 1.5000 | 1.3933 | 1.2866 | 0.1067 | 1.3189 |
| 1 5/8" | 1.625 | 5 | 0.2000 | 1.6251 | 1.4970 | 1.3689 | 0.1281 | 1.3976 |
| 1 3/4" | 1.750 | 5 | 0.2000 | 1.7501 | 1.6220 | 1.4939 | 0.1281 | 1.5157 |
| 1 7/8" | 1.875 | 4 1/2 | 0.2222 | 1.8751 | 1.7328 | 1.5905 | 0.1423 | 1.6240 |
| 2" | 2.000 | 4 1/2 | 0.2222 | 2.0001 | 1.8578 | 1.7155 | 0.1423 | 1.7520 |
| 2 1/4" | 2.250 | 4 | 0.2500 | 2.2501 | 2.0900 | 1.9299 | 0.1601 | 1.9685 |
| 2 1/2" | 2.500 | 4 | 0.2500 | 2.5001 | 2.3400 | 2.1799 | 0.1601 | 2.2047 |
| 2 3/4" | 2.750 | 3 1/2 | 0.2857 | 2.7501 | 2.5671 | 2.3842 | 0.1830 | 2.4213 |
| 3" | 3.000 | 3 1/2 | 0.2857 | 3.0001 | 2.8172 | 2.6342 | 0.1830 | 2.6772 |
| 3 1/4" | 3.250 | 3 1/4 | 0.3077 | 3.2501 | 3.0531 | 2.8561 | 0.1970 | 2.9035 |
| 3 1/2" | 3.500 | 3 1/4 | 0.3077 | 3.5001 | 3.3031 | 3.1061 | 0.1970 | 3.1496 |
| 3 3/4" | 3.750 | 3 | 0.3333 | 3.7502 | 3.5367 | 3.3232 | 0.2135 | 3.3661 |
| 4" | 4.000 | 3 | 0.3333 | 4.0002 | 3.7867 | 3.5732 | 0.2135 | 3.6220 |
| 4 1/4" | 4.250 | 2 7/8 | 0.3478 | 4.2502 | 4.0274 | 3.8047 | 0.2227 | 3.8583 |
| 4 1/2" | 4.500 | 2 7/8 | 0.3478 | 4.5002 | 4.2774 | 4.0547 | 0.2227 | 4.1024 |
| 4 3/4" | 4.751 | 2 3/4 | 0.3637 | 4.7506 | 4.5173 | 4.2766 | 0.2329 | 4.3307 |
| 5" | 5.000 | 2 3/4 | 0.3637 | 5.0002 | 4.7673 | 4.5345 | 0.2329 | 4.5866 |
| 5 1/4" | 5.250 | 2 5/8 | 0.3810 | 5.2502 | 5.0063 | 4.7623 | 0.2439 | 4.8228 |
| 5 1/2" | 5.500 | 2 5/8 | 0.3810 | 5.5002 | 5.2563 | 5.0123 | 0.2439 | 5.0591 |
| 5 3/4" | 5.750 | 2 1/2 | 0.4000 | 5.7502 | 5.4941 | 5.2379 | 0.2561 | 5.2953 |
| 6" | 6.000 | 2 1/2 | 0.4000 | 6.0002 | 5.7441 | 5.4880 | 0.2561 | 5.5512 |
Joseph Whitworth
BSW
Whitworth is a coarse thread devised and standardised by British Engineer Sir Joseph Whitworth (1803 - 87) in Manchester, England in 1841 and is still in use.
British Standard Whitworth
WHITWORTH BSW BRITISH STANDARD BS 84 1956
