ISO METRIC THREADING
P (mm) | Screw with 6g tolerance | Nut screw with 6H tolerance | |||||||||
Ø major d | Ø pitch dm | Ø core dn | Ø pitch Dm | Ø core DN | |||||||
max | min | max | min | max | min | max | min | max | min | ||
M4 | 0.7 | 3.978 | 3.383 | 3.523 | 3.433 | 3.220 | 2.979 | 3.545 | 3.663 | 3.242 | 3.422 |
M5 | 0.8 | 4.976 | 4.826 | 4.456 | 4.361 | 4.110 | 3.842 | 4.480 | 4.605 | 4.134 | 4.334 |
M6 | 1.0 | 5.974 | 5.974 | 5.324 | 5.212 | 4.891 | 4.563 | 5.350 | 5.500 | 4.917 | 5.153 |
M8 | 1.25 | 7.972 | 7.760 | 7.160 | 7.042 | 6.619 | 6.230 | 7.188 | 7.348 | 6.647 | 6.912 |
M10 | 1.5 | 9.968 | 9.732 | 8.994 | 8.862 | 8.344 | 7.888 | 9.026 | 9.206 | 8.376 | 8.676 |
M12 | 1.75 | 11.966 | 11.701 | 10.829 | 10.679 | 10.072 | 9.543 | 10.863 | 11.063 | 10.106 | 10.441 |
M14 | 2.0 | 13.962 | 13.682 | 12.663 | 12.503 | 11.797 | 11.204 | 12.701 | 12.913 | 11.835 | 12.210 |
M16 | 2.0 | 15.962 | 15.682 | 14.663 | 14.503 | 13.797 | 13.204 | 14.701 | 14.913 | 13.835 | 14.210 |
M18 | 2.5 | 17.958 | 17.623 | 16.334 | 16.164 | 15.252 | 14.541 | 16.376 | 16.600 | 15.294 | 15.744 |
M20 | 2.5 | 19.958 | 19.623 | 18.344 | 18.164 | 17.252 | 16.541 | 18.376 | 18.600 | 17.294 | 17.744 |
UK WHITWORTH THREADING (BSW-BSF)
Thread per inch | Major diameter d |
Pitch diameter dm |
Core diameter dn |
|
BSW | ||||
1/4 (0.25) | 20 | 0.2500 | 0.2180 | 0.1860 |
5/16 (0.3125) | 18 | 0.3125 | 0.2769 | 0.2413 |
3/8 (0.375) | 16 | 0.3750 | 0.3350 | 0.2950 |
1/2 (0.5) | 12 | 0.5000 | 0.4466 | 0.3932 |
5/8 (0.625) | 11 | 0.6250 | 0.5668 | 0.5086 |
3/4 (0.75) | 10 | 0.7500 | 0.6860 | 0.6220 |
BSF | ||||
1/4 (0.25) | 26 | 0.2500 | 0.2254 | 0.2008 |
5/16 (0.3125) | 22 | 0.3125 | 0.2834 | 0.2534 |
3/8 (0.375) | 20 | 0.3750 | 0.3430 | 0.3110 |
1/2 (0.5) | 16 | 0.5000 | 0.4600 | 0.4200 |
5/8 (0.625) | 14 | 0.6250 | 0.5793 | 0.5336 |
3/4 (0.75) | 12 | 0.7500 | 0.6966 | 0.6432 |
Fractions (of an inch) are expressed as decimals in the table.
AMERICAN STANDARD THREADING UNC-UNF
Threads per inch |
Screw with tolerance 2 | Nut screw with tolerance 2B | |||||||||||
Ø major d | Ø pitch dm | Ø core dn | Ø minor D | Ø pitch Dm | Ø major Dn | ||||||||
max | min | max | min | max | min | min | max | min | max | min | max | ||
UNC | |||||||||||||
8-32 | 32 | 0.1631 | 0.1571 | 0.1428 | 0.1399 | 0.1259 | 0.130 | 0.139 | 0.1437 | 0.1475 | 0.1640 | ||
10-24 | 24 | 0.1890 | 0.1818 | 0.1619 | 0.1586 | 0.1394 | 0.145 | 0.156 | 0.1629 | 0.1692 | 0.1900 | ||
1/4 | 20 | 0.2489 | 0.2408 | 0.2164 | 0.2127 | 0.1894 | 0.196 | 0.207 | 0.2175 | 0.2224 | 0.2500 | ||
5/16 | 18 | 0.3113 | 0.3026 | 0.2752 | 0.2712 | 0.2452 | 0.252 | 0.265 | 0.2764 | 0.2817 | 0.3125 | ||
3/8 | 16 | 0.3737 | 0.3643 | 0.3331 | 0.3287 | 0.2992 | 0.307 | 0.321 | 0.3344 | 0.3401 | 0.3750 | ||
1/2 | 13 | 0.4985 | 0.4876 | 0.4485 | 0.4435 | 0.4069 | 0.417 | 0.434 | 0.4500 | 0.4565 | 0.5000 | ||
5/8 | 11 | 0.6234 | 0.6113 | 0.5644 | 0.5589 | 0.5152 | 0.527 | 0.546 | 0.5660 | 0.5732 | 0.6250 | ||
3/4 | 10 | 0.7482 | 0.7353 | 0.6832 | 0.6773 | 0.6291 | 0.642 | 0.663 | 0.6850 | 0.6927 | 0.7500 | ||
1 | 8 | 0.9980 | 0.9830 | 0.9168 | 0.9100 | 0.8492 | 0.865 | 0.890 | 0.9188 | 0.9276 | 1.0000 | ||
UNF | |||||||||||||
8-32 | 36 | 0.1632 | 0.1577 | 0.1452 | 0.1424 | 0.1301 | 0.134 | 0.142 | 0.1460 | 0.1496 | 0.1640 | ||
10-32 | 32 | 0.1891 | 0.1831 | 0.1688 | 0.1658 | 0.1519 | 0.156 | 0.164 | 0.1697 | 0.1736 | 0.1900 | ||
1/4 | 28 | 0.2490 | 0.2392 | 0.2258 | 0.2208 | 0.2064 | 0.211 | 0.220 | 0.2268 | 0.2333 | 0.2500 | ||
5/16 | 24 | 0.3114 | 0.3042 | 0.2843 | 0.2806 | 0.2618 | 0.267 | 0.277 | 0.2854 | 0.2902 | 0.3125 | ||
3/8 | 24 | 0.3739 | 0.3667 | 0.3468 | 0.3430 | 0.3243 | 0.330 | 0.340 | 0.3479 | 0.3528 | 0.3750 | ||
1/2 | 20 | 0.4987 | 0.4906 | 0.4662 | 0.4619 | 0.4392 | 0.446 | 0.457 | 0.4675 | 0.4731 | 0.5000 | ||
5/8 | 18 | 0.6236 | 0.6105 | 0.5875 | 0.5805 | 0.5575 | 0.565 | 0.578 | 0.5889 | 0.5980 | 0.6250 | ||
3/4 | 10 | 0.7485 | 0.7391 | 0.7079 | 0.7029 | 0.6740 | 0.682 | 0.696 | 0.7094 | 0.7159 | 0.7500 | ||
1 | 12 | 0.9982 | 0.9868 | 0.9441 | 0.9382 | 0.8890 | 0.910 | 0.928 | 0.9459 | 0.9535 | 1.0000 |
Fractions (of an inch) are expressed as decimals in the table.