Screw Size | Class Thread |
Major Diameter | Pitch Diameter | Minor Diameter |
|||
Basica | Max. | Min. | Max. | Min. | Max. | ||
2-56 | 2A | 0.0860 | 0.0854 | 0.0813 | 0.0738 | 0.0717 | 0.0635 |
2-56 | 3A | 0.0860 | 0.0860 | 0.0819 | 0.0744 | 0.0728 | 0.0641 |
4-40 | 2A | 0.1120 | 0.1112 | 0.1061 | 0.0950 | 0.0925 | 0.0805 |
4-40 | 3A | 0.1120 | 0.1120 | 0.1069 | 0.0958 | 0.0939 | 0.0813 |
6-32 | 2A | 0.1380 | 0.1372 | 0.1312 | 0.1169 | 0.1141 | 0.0989 |
6-32 | 3A | 0.1380 | 0.1380 | 0.1320 | 0.1177 | 0.1156 | 0.0997 |
8-32 | 2A | 0.1640 | 0.1631 | 0.1571 | 0.1428 | 0.1399 | 0.1248 |
8-32 | 3A | 0.1640 | 0.1640 | 0.1580 | 0.1437 | 0.1415 | 0.1257 |
10-24 | 2A | 0.1900 | 0.1890 | 0.1818 | 0.1619 | 0.1586 | 0.1379 |
10-24 | 3A | 0.1900 | 0.1900 | 0.1828 | 0.1629 | 0.1604 | 0.1389 |
10-32 | 2A | 0.1900 | 0.1891 | 0.1831 | 0.1688 | 0.1658 | 0.1508 |
10-32 | 3A | 0.1900 | 0.1900 | 0.1840 | 0.1697 | 0.1674 | 0.1517 |
1/4-20 | 2A | 0.2500 | 0.2489 | 0.2408 | 0.2164 | 0.2127 | 0.1876 |
1/4-20 | 3A | 0.2500 | 0.2500 | 0.2419 | 0.2175 | 0.2147 | 0.1887 |
1/4-28 | 2A | 0.2500 | 0.2490 | 0.2425 | 0.2258 | 0.2225 | 0.2052 |
1/4-28 | 3A | 0.2500 | 0.2500 | 0.2435 | 0.2268 | 0.2243 | 0.2062 |
5/16-18 | 2A | 0.3125 | 0.3113 | 0.3026 | 0.2752 | 0.2712 | 0.2431 |
5/16-18 | 3A | 0.3125 | 0.3125 | 0.3038 | 0.2764 | 0.2734 | 0.2443 |
5/16-24 | 2A | 0.3125 | 0.3114 | 0.3042 | 0.2843 | 0.2806 | 0.2603 |
5/16-24 | 3A | 0.3125 | 0.3125 | 0.3053 | 0.2854 | 0.2827 | 0.2614 |
3/8-16 | 2A | 0.3750 | 0.3737 | 0.3643 | 0.3331 | 0.3287 | 0.2970 |
3/8-16 | 3A | 0.3750 | 0.3750 | 0.3656 | 0.3344 | 0.3311 | 0.2983 |
3/8-24 | 2A | 0.3750 | 0.3739 | 0.3667 | 0.3468 | 0.3430 | 0.3228 |
3/8-24 | 3A | 0.3750 | 0.3750 | 0.3678 | 0.3479 | 0.3450 | 0.3239 |
7/16-14 | 2A | 0.4375 | 0.4361 | 0.4258 | 0.3897 | 0.3850 | 0.3485 |
7/16-14 | 3A | 0.4375 | 0.4375 | 0.4272 | 0.3911 | 0.3876 | 0.3499 |
7/16-20 | 2A | 0.4375 | 0.4362 | 0.4281 | 0.4037 | 0.3995 | 0.3749 |
7/16-20 | 3A | 0.4375 | 0.4375 | 0.4294 | 0.4050 | 0.4019 | 0.3762 |
1/2-13 | 2A | 0.5000 | 0.4985 | 0.4876 | 0.4485 | 0.4435 | 0.4041 |
1/2-13 | 3A | 0.5000 | 0.5000 | 0.4891 | 0.4500 | 0.4463 | 0.4056 |
1/2-20 | 2A | 0.5000 | 0.4987 | 0.4906 | 0.4662 | 0.4619 | 0.4374 |
1/2-20 | 3A | 0.5000 | 0.5000 | 0.4919 | 0.4675 | 0.4643 | 0.4387 |
9/16-12 | 2A | 0.5625 | 0.5609 | 0.5495 | 0.5068 | 0.5016 | 0.4617 |
9/16-12 | 3A | 0.5625 | 0.5609 | 0.5495 | 0.5068 | 0.5016 | 0.4617 |
9/16-14 | 2A | 0.5625 | 0.5510 | 0.5507 | 0.5146 | 0.5096 | 0.4760 |
9/16-16 | 2A | 0.5625 | 0.5611 | 0.5517 | 0.5205 | 0.5158 | 0.4866 |
9/16-16 | 3A | 0.5625 | 0.5625 | 0.5531 | 0.5219 | 0.5184 | 0.4880 |
9/16-18 | 2A | 0.5625 | 0.5611 | 0.5524 | 0.5250 | 0.5205 | 0.4950 |
9/16-18 | 3A | 0.5625 | 0.5625 | 0.5538 | 0.5264 | 0.5230 | 0.4964 |
9/16-20 | 2A | 0.5625 | 0.5612 | 0.5531 | 0.5287 | 0.5245 | 0.5017 |
9/16-20 | 3A | 0.5625 | 0.5625 | 0.5544 | 0.5300 | 0.5268 | 0.5030 |
9/16-24 | 2A | 0.5625 | 0.5613 | 0.5541 | 0.5342 | 0.5303 | 0.5117 |
9/16-24 | 3A | 0.5625 | 0.5625 | 0.5553 | 0.5354 | 0.5325 | 0.5129 |
9/16-32 | 2A | 0.5625 | 0.5615 | 0.5555 | 0.5412 | 0.5377 | 0.5243 |
9/16-32 | 3A | 0.5625 | 0.5625 | 0.5565 | 0.5422 | 0.5396 | 0.5253 |
5/8-11 | 2A | 0.6250 | 0.6234 | 0.6113 | 0.5644 | 0.5589 | 0.5119 |
5/8-11 | 3A | 0.6250 | 0.6250 | 0.6129 | 0.5660 | 0.5619 | 0.5135 |
5/8-18 | 2A | 0.6250 | 0.6236 | 0.6149 | 0.5875 | 0.5828 | 0.5554 |
5/8-18 | 3A | 0.6250 | 0.6250 | 0.6163 | 0.5889 | 0.5854 | 0.5568 |
3/4-10 | 2A | 0.7500 | 0.7482 | 0.7353 | 0.6832 | 0.6773 | 0.6255 |
3/4-10 | 3A | 0.7500 | 0.7500 | 0.7371 | 0.6850 | 0.6806 | 0.6273 |
3/4-16 | 2A | 0.7500 | 0.7485 | 0.7391 | 0.7079 | 0.7029 | 0.6718 |
3/4-16 | 3A | 0.7500 | 0.7500 | 0.7406 | 0.7094 | 0.7056 | 0.6733 |
7/8 -9 | 2A | 0.8750 | 0.8731 | 0.8592 | 0.8009 | 0.7946 | 0.7368 |
7/8 -9 | 3A | 0.8750 | 0.8750 | 0.8611 | 0.8028 | 0.7981 | 0.7387 |
7/8-14 | 2A | 0.8750 | 0.8734 | 0.8631 | 0.8270 | 0.8216 | 0.7858 |
7/8-14 | 3A | 0.8750 | 0.8750 | 0.8647 | 0.8286 | 0.8245 | 0.7874 |
1 -8 | 2A | 1.0000 | 0.9980 | 0.9830 | 0.9168 | 0.9100 | 0.8446 |
1 -8 | 3A | 1.0000 | 1.0000 | 0.9850 | 0.9188 | 0.9137 | 0.8466 |
1 -12 | 2A | 1.0000 | 0.9982 | 0.9868 | 0.9441 | 0.9382 | 0.8960 |
1 -12 | 3A | 1.0000 | 1.0000 | 0.9886 | 0.9459 | 0.9415 | 0.8978 |
1-1/8-7 | 2A | 1.1250 | 1.1228 | 1.1064 | 1.0300 | 1.0228 | 0.9475 |
1-1/8-12 | 2A | 1.1250 | 1.1232 | 1.1118 | 1.0691 | 1.0631 | 1.0210 |
1-1/4-7 | 2A | 1.2500 | 1.2478 | 1.2314 | 1.1550 | 1.1476 | 1.0725 |
1-1/4-12 | 2A | 1.2500 | 1.2482 | 1.2368 | 1.1941 | 1.1879 | 1.1460 |
1-3/8-6 | 2A | 1.3750 | 1.3726 | 1.3544 | 1.2643 | 1.2563 | 1.1681 |
1-3/8-12 | 2A | 1.3750 | 1.3731 | 1.3617 | 1.3190 | 1.3127 | 1.2709 |
1-1/2-6 | 2A | 1.5000 | 1.4976 | 1.4794 | 1.3893 | 1.3812 | 1.2931 |
1-1/2-12 | 2A | 1.5000 | 1.4981 | 1.4867 | 1.4440 | 1.4376 | 1.3959 |
1-3/4-5 | 2A | 1.7500 | 1.7473 | 1.7268 | 1.6174 | 1.6085 | 1.5019 |
2 – 6 | 2A | 2.0000 | 1.9971 | 1.9751 | 1.8528 | 1.8433 | 1.7245 |
Original source: https://www.engineersedge.com/screw_threads_chart.htm