Tool
Thread Size Lookup
Type the thread callout from your drawing. See the limits of size for the external and internal thread, in mm and inches.
Covers metric M1.6 to M39 with common fine pitches, and pipe sizes 1/16 to 2.
These are the standard limits for the thread itself, not a statement of any shop's machining capability. Check the finished thread with a go/no-go gauge of the right system. Where a gauge and this page disagree, the gauge and the standard govern.
Reference
Full tables
| Thread | Pitch | External thread (6g) | Internal thread (6H) | Tap drill (reference) | |||
|---|---|---|---|---|---|---|---|
| Major diameter | Pitch diameter | Major diameter, Min | Pitch diameter | Minor diameter | |||
| M1.6 | 0.35 mm0.0138 in | 1.496 – 1.581 mm0.0589 – 0.0622 in | 1.291 – 1.354 mm0.0508 – 0.0533 in | 1.600 mm0.0630 in | 1.373 – 1.458 mm0.0541 – 0.0574 in | 1.221 – 1.321 mm0.0481 – 0.0520 in | 1.25 mm0.0492 in |
| M1.8 | 0.35 mm0.0138 in | 1.696 – 1.781 mm0.0668 – 0.0701 in | 1.491 – 1.554 mm0.0587 – 0.0612 in | 1.800 mm0.0709 in | 1.573 – 1.658 mm0.0619 – 0.0653 in | 1.421 – 1.521 mm0.0559 – 0.0599 in | 1.45 mm0.0571 in |
| M2 | 0.4 mm0.0157 in | 1.886 – 1.981 mm0.0743 – 0.0780 in | 1.654 – 1.721 mm0.0651 – 0.0678 in | 2.000 mm0.0787 in | 1.740 – 1.830 mm0.0685 – 0.0720 in | 1.567 – 1.679 mm0.0617 – 0.0661 in | 1.6 mm0.0630 in |
| M2.2 | 0.45 mm0.0177 in | 2.080 – 2.180 mm0.0819 – 0.0858 in | 1.817 – 1.888 mm0.0715 – 0.0743 in | 2.200 mm0.0866 in | 1.908 – 2.003 mm0.0751 – 0.0789 in | 1.713 – 1.838 mm0.0674 – 0.0724 in | 1.75 mm0.0689 in |
| M2.5 | 0.45 mm0.0177 in | 2.380 – 2.480 mm0.0937 – 0.0976 in | 2.117 – 2.188 mm0.0833 – 0.0861 in | 2.500 mm0.0984 in | 2.208 – 2.303 mm0.0869 – 0.0907 in | 2.013 – 2.138 mm0.0793 – 0.0842 in | 2.05 mm0.0807 in |
| M3 | 0.5 mm0.0197 in | 2.874 – 2.980 mm0.1131 – 0.1173 in | 2.580 – 2.655 mm0.1016 – 0.1045 in | 3.000 mm0.1181 in | 2.675 – 2.775 mm0.1053 – 0.1093 in | 2.459 – 2.599 mm0.0968 – 0.1023 in | 2.5 mm0.0984 in |
| M3.5 | 0.6 mm0.0236 in | 3.354 – 3.479 mm0.1320 – 0.1370 in | 3.004 – 3.089 mm0.1183 – 0.1216 in | 3.500 mm0.1378 in | 3.110 – 3.222 mm0.1224 – 0.1269 in | 2.850 – 3.010 mm0.1122 – 0.1185 in | 2.9 mm0.1142 in |
| M4 | 0.7 mm0.0276 in | 3.838 – 3.978 mm0.1511 – 0.1566 in | 3.433 – 3.523 mm0.1352 – 0.1387 in | 4.000 mm0.1575 in | 3.545 – 3.663 mm0.1396 – 0.1442 in | 3.242 – 3.422 mm0.1276 – 0.1347 in | 3.3 mm0.1299 in |
| M5 | 0.8 mm0.0315 in | 4.826 – 4.976 mm0.1900 – 0.1959 in | 4.361 – 4.456 mm0.1717 – 0.1754 in | 5.000 mm0.1969 in | 4.480 – 4.605 mm0.1764 – 0.1813 in | 4.134 – 4.334 mm0.1628 – 0.1706 in | 4.2 mm0.1654 in |
| M5x0.5 | 0.5 mm0.0197 in | 4.874 – 4.980 mm0.1919 – 0.1961 in | 4.580 – 4.655 mm0.1803 – 0.1833 in | 5.000 mm0.1969 in | 4.675 – 4.775 mm0.1841 – 0.1880 in | 4.459 – 4.599 mm0.1756 – 0.1811 in | 4.5 mm0.1772 in |
| M6 | 1 mm0.0394 in | 5.794 – 5.974 mm0.2281 – 0.2352 in | 5.212 – 5.324 mm0.2052 – 0.2096 in | 6.000 mm0.2362 in | 5.350 – 5.500 mm0.2106 – 0.2165 in | 4.917 – 5.153 mm0.1936 – 0.2029 in | 5.0 mm0.1969 in |
| M6x0.75 | 0.75 mm0.0295 in | 5.838 – 5.978 mm0.2298 – 0.2354 in | 5.391 – 5.491 mm0.2122 – 0.2162 in | 6.000 mm0.2362 in | 5.513 – 5.645 mm0.2170 – 0.2222 in | 5.188 – 5.378 mm0.2043 – 0.2117 in | 5.2 mm0.2047 in |
| M7 | 1 mm0.0394 in | 6.794 – 6.974 mm0.2675 – 0.2746 in | 6.212 – 6.324 mm0.2446 – 0.2490 in | 7.000 mm0.2756 in | 6.350 – 6.500 mm0.2500 – 0.2559 in | 5.917 – 6.153 mm0.2330 – 0.2422 in | 6.0 mm0.2362 in |
| M8 | 1.25 mm0.0492 in | 7.760 – 7.972 mm0.3055 – 0.3139 in | 7.042 – 7.160 mm0.2772 – 0.2819 in | 8.000 mm0.3150 in | 7.188 – 7.348 mm0.2830 – 0.2893 in | 6.647 – 6.912 mm0.2617 – 0.2721 in | 6.8 mm0.2677 in |
| M8x1 | 1 mm0.0394 in | 7.794 – 7.974 mm0.3069 – 0.3139 in | 7.212 – 7.324 mm0.2839 – 0.2883 in | 8.000 mm0.3150 in | 7.350 – 7.500 mm0.2894 – 0.2953 in | 6.917 – 7.153 mm0.2723 – 0.2816 in | 7.0 mm0.2756 in |
| M8x0.75 | 0.75 mm0.0295 in | 7.838 – 7.978 mm0.3086 – 0.3141 in | 7.391 – 7.491 mm0.2910 – 0.2949 in | 8.000 mm0.3150 in | 7.513 – 7.645 mm0.2958 – 0.3010 in | 7.188 – 7.378 mm0.2830 – 0.2905 in | 7.2 mm0.2835 in |
| M10 | 1.5 mm0.0591 in | 9.732 – 9.968 mm0.3831 – 0.3924 in | 8.862 – 8.994 mm0.3489 – 0.3541 in | 10.000 mm0.3937 in | 9.026 – 9.206 mm0.3554 – 0.3624 in | 8.376 – 8.676 mm0.3298 – 0.3416 in | 8.5 mm0.3346 in |
| M10x1.25 | 1.25 mm0.0492 in | 9.760 – 9.972 mm0.3843 – 0.3926 in | 9.042 – 9.160 mm0.3560 – 0.3606 in | 10.000 mm0.3937 in | 9.188 – 9.348 mm0.3617 – 0.3680 in | 8.647 – 8.912 mm0.3404 – 0.3509 in | 8.8 mm0.3465 in |
| M10x1 | 1 mm0.0394 in | 9.794 – 9.974 mm0.3856 – 0.3927 in | 9.212 – 9.324 mm0.3627 – 0.3671 in | 10.000 mm0.3937 in | 9.350 – 9.500 mm0.3681 – 0.3740 in | 8.917 – 9.153 mm0.3511 – 0.3604 in | 9.0 mm0.3543 in |
| M10x0.75 | 0.75 mm0.0295 in | 9.838 – 9.978 mm0.3873 – 0.3928 in | 9.391 – 9.491 mm0.3697 – 0.3737 in | 10.000 mm0.3937 in | 9.513 – 9.645 mm0.3745 – 0.3797 in | 9.188 – 9.378 mm0.3617 – 0.3692 in | 9.2 mm0.3622 in |
| M12 | 1.75 mm0.0689 in | 11.701 – 11.966 mm0.4607 – 0.4711 in | 10.679 – 10.829 mm0.4204 – 0.4263 in | 12.000 mm0.4724 in | 10.863 – 11.063 mm0.4277 – 0.4356 in | 10.106 – 10.441 mm0.3979 – 0.4111 in | 10.2 mm0.4016 in |
| M12x1.5 | 1.5 mm0.0591 in | 11.732 – 11.968 mm0.4619 – 0.4712 in | 10.854 – 10.994 mm0.4273 – 0.4328 in | 12.000 mm0.4724 in | 11.026 – 11.216 mm0.4341 – 0.4416 in | 10.376 – 10.676 mm0.4085 – 0.4203 in | 10.5 mm0.4134 in |
| M12x1.25 | 1.25 mm0.0492 in | 11.760 – 11.972 mm0.4630 – 0.4713 in | 11.028 – 11.160 mm0.4342 – 0.4394 in | 12.000 mm0.4724 in | 11.188 – 11.368 mm0.4405 – 0.4476 in | 10.647 – 10.912 mm0.4192 – 0.4296 in | 10.8 mm0.4252 in |
| M12x1 | 1 mm0.0394 in | 11.794 – 11.974 mm0.4643 – 0.4714 in | 11.206 – 11.324 mm0.4412 – 0.4458 in | 12.000 mm0.4724 in | 11.350 – 11.510 mm0.4469 – 0.4531 in | 10.917 – 11.153 mm0.4298 – 0.4391 in | 11.0 mm0.4331 in |
| M14 | 2 mm0.0787 in | 13.682 – 13.962 mm0.5387 – 0.5497 in | 12.503 – 12.663 mm0.4922 – 0.4985 in | 14.000 mm0.5512 in | 12.701 – 12.913 mm0.5000 – 0.5084 in | 11.835 – 12.210 mm0.4659 – 0.4807 in | 12.0 mm0.4724 in |
| M14x1.5 | 1.5 mm0.0591 in | 13.732 – 13.968 mm0.5406 – 0.5499 in | 12.854 – 12.994 mm0.5061 – 0.5116 in | 14.000 mm0.5512 in | 13.026 – 13.216 mm0.5128 – 0.5203 in | 12.376 – 12.676 mm0.4872 – 0.4991 in | 12.5 mm0.4921 in |
| M16 | 2 mm0.0787 in | 15.682 – 15.962 mm0.6174 – 0.6284 in | 14.503 – 14.663 mm0.5710 – 0.5773 in | 16.000 mm0.6299 in | 14.701 – 14.913 mm0.5788 – 0.5871 in | 13.835 – 14.210 mm0.5447 – 0.5594 in | 14.0 mm0.5512 in |
| M16x1.5 | 1.5 mm0.0591 in | 15.732 – 15.968 mm0.6194 – 0.6287 in | 14.854 – 14.994 mm0.5848 – 0.5903 in | 16.000 mm0.6299 in | 15.026 – 15.216 mm0.5916 – 0.5991 in | 14.376 – 14.676 mm0.5660 – 0.5778 in | 14.5 mm0.5709 in |
| M16x1 | 1 mm0.0394 in | 15.794 – 15.974 mm0.6218 – 0.6289 in | 15.206 – 15.324 mm0.5987 – 0.6033 in | 16.000 mm0.6299 in | 15.350 – 15.510 mm0.6043 – 0.6106 in | 14.917 – 15.153 mm0.5873 – 0.5966 in | 15.0 mm0.5906 in |
| M18 | 2.5 mm0.0984 in | 17.623 – 17.958 mm0.6938 – 0.7070 in | 16.164 – 16.334 mm0.6364 – 0.6431 in | 18.000 mm0.7087 in | 16.376 – 16.600 mm0.6447 – 0.6535 in | 15.294 – 15.744 mm0.6021 – 0.6198 in | 15.5 mm0.6102 in |
| M18x2 | 2 mm0.0787 in | 17.682 – 17.962 mm0.6961 – 0.7072 in | 16.503 – 16.663 mm0.6497 – 0.6560 in | 18.000 mm0.7087 in | 16.701 – 16.913 mm0.6575 – 0.6659 in | 15.835 – 16.210 mm0.6234 – 0.6382 in | 16.0 mm0.6299 in |
| M18x1.5 | 1.5 mm0.0591 in | 17.732 – 17.968 mm0.6981 – 0.7074 in | 16.854 – 16.994 mm0.6635 – 0.6691 in | 18.000 mm0.7087 in | 17.026 – 17.216 mm0.6703 – 0.6778 in | 16.376 – 16.676 mm0.6447 – 0.6565 in | 16.5 mm0.6496 in |
| M20 | 2.5 mm0.0984 in | 19.623 – 19.958 mm0.7726 – 0.7857 in | 18.164 – 18.334 mm0.7151 – 0.7218 in | 20.000 mm0.7874 in | 18.376 – 18.600 mm0.7235 – 0.7323 in | 17.294 – 17.744 mm0.6809 – 0.6986 in | 17.5 mm0.6890 in |
| M20x2 | 2 mm0.0787 in | 19.682 – 19.962 mm0.7749 – 0.7859 in | 18.503 – 18.663 mm0.7285 – 0.7348 in | 20.000 mm0.7874 in | 18.701 – 18.913 mm0.7363 – 0.7446 in | 17.835 – 18.210 mm0.7022 – 0.7169 in | 18.0 mm0.7087 in |
| M20x1.5 | 1.5 mm0.0591 in | 19.732 – 19.968 mm0.7769 – 0.7861 in | 18.854 – 18.994 mm0.7423 – 0.7478 in | 20.000 mm0.7874 in | 19.026 – 19.216 mm0.7491 – 0.7565 in | 18.376 – 18.676 mm0.7235 – 0.7353 in | 18.5 mm0.7283 in |
| M20x1 | 1 mm0.0394 in | 19.794 – 19.974 mm0.7793 – 0.7864 in | 19.206 – 19.324 mm0.7561 – 0.7608 in | 20.000 mm0.7874 in | 19.350 – 19.510 mm0.7618 – 0.7681 in | 18.917 – 19.153 mm0.7448 – 0.7541 in | 19.0 mm0.7480 in |
| M22 | 2.5 mm0.0984 in | 21.623 – 21.958 mm0.8513 – 0.8645 in | 20.164 – 20.334 mm0.7939 – 0.8006 in | 22.000 mm0.8661 in | 20.376 – 20.600 mm0.8022 – 0.8110 in | 19.294 – 19.744 mm0.7596 – 0.7773 in | 19.5 mm0.7677 in |
| M22x2 | 2 mm0.0787 in | 21.682 – 21.962 mm0.8536 – 0.8646 in | 20.503 – 20.663 mm0.8072 – 0.8135 in | 22.000 mm0.8661 in | 20.701 – 20.913 mm0.8150 – 0.8233 in | 19.835 – 20.210 mm0.7809 – 0.7957 in | 20.0 mm0.7874 in |
| M22x1.5 | 1.5 mm0.0591 in | 21.732 – 21.968 mm0.8556 – 0.8649 in | 20.854 – 20.994 mm0.8210 – 0.8265 in | 22.000 mm0.8661 in | 21.026 – 21.216 mm0.8278 – 0.8353 in | 20.376 – 20.676 mm0.8022 – 0.8140 in | 20.5 mm0.8071 in |
| M24 | 3 mm0.1181 in | 23.577 – 23.952 mm0.9282 – 0.9430 in | 21.803 – 22.003 mm0.8584 – 0.8663 in | 24.000 mm0.9449 in | 22.051 – 22.316 mm0.8681 – 0.8786 in | 20.752 – 21.252 mm0.8170 – 0.8367 in | 21.0 mm0.8268 in |
| M24x2 | 2 mm0.0787 in | 23.682 – 23.962 mm0.9324 – 0.9434 in | 22.493 – 22.663 mm0.8856 – 0.8922 in | 24.000 mm0.9449 in | 22.701 – 22.925 mm0.8937 – 0.9026 in | 21.835 – 22.210 mm0.8596 – 0.8744 in | 22.0 mm0.8661 in |
| M26x1.5 | 1.5 mm0.0591 in | 25.732 – 25.968 mm1.0131 – 1.0224 in | 24.844 – 24.994 mm0.9781 – 0.9840 in | 26.000 mm1.0236 in | 25.026 – 25.226 mm0.9853 – 0.9931 in | 24.376 – 24.676 mm0.9597 – 0.9715 in | 24.5 mm0.9646 in |
| M27 | 3 mm0.1181 in | 26.577 – 26.952 mm1.0463 – 1.0611 in | 24.803 – 25.003 mm0.9765 – 0.9844 in | 27.000 mm1.0630 in | 25.051 – 25.316 mm0.9863 – 0.9967 in | 23.752 – 24.252 mm0.9351 – 0.9548 in | 24.0 mm0.9449 in |
| M27x2 | 2 mm0.0787 in | 26.682 – 26.962 mm1.0505 – 1.0615 in | 25.493 – 25.663 mm1.0037 – 1.0104 in | 27.000 mm1.0630 in | 25.701 – 25.925 mm1.0119 – 1.0207 in | 24.835 – 25.210 mm0.9778 – 0.9925 in | 25.0 mm0.9843 in |
| M27x1.5 | 1.5 mm0.0591 in | 26.732 – 26.968 mm1.0524 – 1.0617 in | 25.844 – 25.994 mm1.0175 – 1.0234 in | 27.000 mm1.0630 in | 26.026 – 26.226 mm1.0246 – 1.0325 in | 25.376 – 25.676 mm0.9991 – 1.0109 in | 25.5 mm1.0039 in |
| M30 | 3.5 mm0.1378 in | 29.522 – 29.947 mm1.1623 – 1.1790 in | 27.462 – 27.674 mm1.0812 – 1.0895 in | 30.000 mm1.1811 in | 27.727 – 28.007 mm1.0916 – 1.1026 in | 26.211 – 26.771 mm1.0319 – 1.0540 in | 26.5 mm1.0433 in |
| M30x2 | 2 mm0.0787 in | 29.682 – 29.962 mm1.1686 – 1.1796 in | 28.493 – 28.663 mm1.1218 – 1.1285 in | 30.000 mm1.1811 in | 28.701 – 28.925 mm1.1300 – 1.1388 in | 27.835 – 28.210 mm1.0959 – 1.1106 in | 28.0 mm1.1024 in |
| M30x1.5 | 1.5 mm0.0591 in | 29.732 – 29.968 mm1.1706 – 1.1798 in | 28.844 – 28.994 mm1.1356 – 1.1415 in | 30.000 mm1.1811 in | 29.026 – 29.226 mm1.1428 – 1.1506 in | 28.376 – 28.676 mm1.1172 – 1.1290 in | 28.5 mm1.1220 in |
| M33 | 3.5 mm0.1378 in | 32.522 – 32.947 mm1.2804 – 1.2971 in | 30.462 – 30.674 mm1.1993 – 1.2076 in | 33.000 mm1.2992 in | 30.727 – 31.007 mm1.2097 – 1.2207 in | 29.211 – 29.771 mm1.1500 – 1.1721 in | 29.5 mm1.1614 in |
| M33x2 | 2 mm0.0787 in | 32.682 – 32.962 mm1.2867 – 1.2977 in | 31.493 – 31.663 mm1.2399 – 1.2466 in | 33.000 mm1.2992 in | 31.701 – 31.925 mm1.2481 – 1.2569 in | 30.835 – 31.210 mm1.2140 – 1.2287 in | 31.0 mm1.2205 in |
| M35x1.5 | 1.5 mm0.0591 in | 34.732 – 34.968 mm1.3674 – 1.3767 in | 33.844 – 33.994 mm1.3324 – 1.3383 in | 35.000 mm1.3780 in | 34.026 – 34.226 mm1.3396 – 1.3475 in | 33.376 – 33.676 mm1.3140 – 1.3258 in | 33.5 mm1.3189 in |
| M36 | 4 mm0.1575 in | 35.465 – 35.940 mm1.3963 – 1.4150 in | 33.118 – 33.342 mm1.3039 – 1.3127 in | 36.000 mm1.4173 in | 33.402 – 33.702 mm1.3150 – 1.3269 in | 31.670 – 32.270 mm1.2469 – 1.2705 in | 32.0 mm1.2598 in |
| M36x3 | 3 mm0.1181 in | 35.577 – 35.952 mm1.4007 – 1.4154 in | 33.803 – 34.003 mm1.3308 – 1.3387 in | 36.000 mm1.4173 in | 34.051 – 34.316 mm1.3406 – 1.3510 in | 32.752 – 33.252 mm1.2894 – 1.3091 in | 33.0 mm1.2992 in |
| M36x2 | 2 mm0.0787 in | 35.682 – 35.962 mm1.4048 – 1.4158 in | 34.493 – 34.663 mm1.3580 – 1.3647 in | 36.000 mm1.4173 in | 34.701 – 34.925 mm1.3662 – 1.3750 in | 33.835 – 34.210 mm1.3321 – 1.3469 in | 34.0 mm1.3386 in |
| M39 | 4 mm0.1575 in | 38.465 – 38.940 mm1.5144 – 1.5331 in | 36.118 – 36.342 mm1.4220 – 1.4308 in | 39.000 mm1.5354 in | 36.402 – 36.702 mm1.4331 – 1.4450 in | 34.670 – 35.270 mm1.3650 – 1.3886 in | 35.0 mm1.3780 in |
| M39x3 | 3 mm0.1181 in | 38.577 – 38.952 mm1.5188 – 1.5335 in | 36.803 – 37.003 mm1.4489 – 1.4568 in | 39.000 mm1.5354 in | 37.051 – 37.316 mm1.4587 – 1.4691 in | 35.752 – 36.252 mm1.4076 – 1.4272 in | 36.0 mm1.4173 in |
| M40x1.5 | 1.5 mm0.0591 in | 39.732 – 39.968 mm1.5643 – 1.5735 in | 38.844 – 38.994 mm1.5293 – 1.5352 in | 40.000 mm1.5748 in | 39.026 – 39.226 mm1.5365 – 1.5443 in | 38.376 – 38.676 mm1.5109 – 1.5227 in | 38.5 mm1.5157 in |
| M42x2 | 2 mm0.0787 in | 41.682 – 41.962 mm1.6410 – 1.6520 in | 40.493 – 40.663 mm1.5942 – 1.6009 in | 42.000 mm1.6535 in | 40.701 – 40.925 mm1.6024 – 1.6112 in | 39.835 – 40.210 mm1.5683 – 1.5831 in | 40.0 mm1.5748 in |
| Size | TPI | Pitch | Thread height | At gauge plane | Gauge length | Rp diameter tolerance | |||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Major diameter | Pitch diameter | Minor diameter | Basic | Tolerance | Max | Min | |||||
| 1/16 | 28 | 0.907 mm0.0357 in | 0.581 mm0.0229 in | 7.723 mm0.3041 in | 7.142 mm0.2812 in | 6.561 mm0.2583 in | 4.0 mm0.1575 in | ±0.9 mm±0.0354 in±1 turn | 4.9 mm0.1929 in | 3.1 mm0.1220 in | ±0.071 mm−0.0028 – +0.0028 in |
| 1/8 | 28 | 0.907 mm0.0357 in | 0.581 mm0.0229 in | 9.728 mm0.3830 in | 9.147 mm0.3601 in | 8.566 mm0.3372 in | 4.0 mm0.1575 in | ±0.9 mm±0.0354 in±1 turn | 4.9 mm0.1929 in | 3.1 mm0.1220 in | ±0.071 mm−0.0028 – +0.0028 in |
| 1/4 | 19 | 1.337 mm0.0526 in | 0.856 mm0.0337 in | 13.157 mm0.5180 in | 12.301 mm0.4843 in | 11.445 mm0.4506 in | 6.0 mm0.2362 in | ±1.3 mm±0.0512 in±1 turn | 7.3 mm0.2874 in | 4.7 mm0.1850 in | ±0.104 mm−0.0041 – +0.0041 in |
| 3/8 | 19 | 1.337 mm0.0526 in | 0.856 mm0.0337 in | 16.662 mm0.6560 in | 15.806 mm0.6223 in | 14.950 mm0.5886 in | 6.4 mm0.2520 in | ±1.3 mm±0.0512 in±1 turn | 7.7 mm0.3031 in | 5.1 mm0.2008 in | ±0.104 mm−0.0041 – +0.0041 in |
| 1/2 | 14 | 1.814 mm0.0714 in | 1.162 mm0.0457 in | 20.955 mm0.8250 in | 19.793 mm0.7793 in | 18.631 mm0.7335 in | 8.2 mm0.3228 in | ±1.8 mm±0.0709 in±1 turn | 10.0 mm0.3937 in | 6.4 mm0.2520 in | ±0.142 mm−0.0056 – +0.0056 in |
| 3/4 | 14 | 1.814 mm0.0714 in | 1.162 mm0.0457 in | 26.441 mm1.0410 in | 25.279 mm0.9952 in | 24.117 mm0.9495 in | 9.5 mm0.3740 in | ±1.8 mm±0.0709 in±1 turn | 11.3 mm0.4449 in | 7.7 mm0.3031 in | ±0.142 mm−0.0056 – +0.0056 in |
| 1 | 11 | 2.309 mm0.0909 in | 1.479 mm0.0582 in | 33.249 mm1.3090 in | 31.770 mm1.2508 in | 30.291 mm1.1926 in | 10.4 mm0.4094 in | ±2.3 mm±0.0906 in±1 turn | 12.7 mm0.5000 in | 8.1 mm0.3189 in | ±0.180 mm−0.0071 – +0.0071 in |
| 1 1/4 | 11 | 2.309 mm0.0909 in | 1.479 mm0.0582 in | 41.910 mm1.6500 in | 40.431 mm1.5918 in | 38.952 mm1.5335 in | 12.7 mm0.5000 in | ±2.3 mm±0.0906 in±1 turn | 15.0 mm0.5906 in | 10.4 mm0.4094 in | ±0.180 mm−0.0071 – +0.0071 in |
| 1 1/2 | 11 | 2.309 mm0.0909 in | 1.479 mm0.0582 in | 47.803 mm1.8820 in | 46.324 mm1.8238 in | 44.845 mm1.7656 in | 12.7 mm0.5000 in | ±2.3 mm±0.0906 in±1 turn | 15.0 mm0.5906 in | 10.4 mm0.4094 in | ±0.180 mm−0.0071 – +0.0071 in |
| 2 | 11 | 2.309 mm0.0909 in | 1.479 mm0.0582 in | 59.614 mm2.3470 in | 58.135 mm2.2888 in | 56.656 mm2.2306 in | 15.9 mm0.6260 in | ±2.3 mm±0.0906 in±1 turn | 18.2 mm0.7165 in | 13.6 mm0.5354 in | ±0.180 mm−0.0071 – +0.0071 in |
| Size | TPI | Pitch | Basic | Internal thread | External thread | |||||
|---|---|---|---|---|---|---|---|---|---|---|
| Major diameter | Pitch diameter | Minor diameter | Pitch diameter | Minor diameter | Pitch diameter, A | Pitch diameter, B | Major diameter | |||
| 1/16 | 28 | 0.907 mm0.0357 in | 7.723 mm0.3041 in | 7.142 mm0.2812 in | 6.561 mm0.2583 in | 7.142 – 7.249 mm0.2812 – 0.2854 in | 6.561 – 6.843 mm0.2583 – 0.2694 in | 7.035 – 7.142 mm0.2770 – 0.2812 in | 6.928 – 7.142 mm0.2728 – 0.2812 in | 7.509 – 7.723 mm0.2956 – 0.3041 in |
| 1/8 | 28 | 0.907 mm0.0357 in | 9.728 mm0.3830 in | 9.147 mm0.3601 in | 8.566 mm0.3372 in | 9.147 – 9.254 mm0.3601 – 0.3643 in | 8.566 – 8.848 mm0.3372 – 0.3483 in | 9.040 – 9.147 mm0.3559 – 0.3601 in | 8.933 – 9.147 mm0.3517 – 0.3601 in | 9.514 – 9.728 mm0.3746 – 0.3830 in |
| 1/4 | 19 | 1.337 mm0.0526 in | 13.157 mm0.5180 in | 12.301 mm0.4843 in | 11.445 mm0.4506 in | 12.301 – 12.426 mm0.4843 – 0.4892 in | 11.445 – 11.890 mm0.4506 – 0.4681 in | 12.176 – 12.301 mm0.4794 – 0.4843 in | 12.051 – 12.301 mm0.4744 – 0.4843 in | 12.907 – 13.157 mm0.5081 – 0.5180 in |
| 3/8 | 19 | 1.337 mm0.0526 in | 16.662 mm0.6560 in | 15.806 mm0.6223 in | 14.950 mm0.5886 in | 15.806 – 15.931 mm0.6223 – 0.6272 in | 14.950 – 15.395 mm0.5886 – 0.6061 in | 15.681 – 15.806 mm0.6174 – 0.6223 in | 15.556 – 15.806 mm0.6124 – 0.6223 in | 16.412 – 16.662 mm0.6461 – 0.6560 in |
| 1/2 | 14 | 1.814 mm0.0714 in | 20.955 mm0.8250 in | 19.793 mm0.7793 in | 18.631 mm0.7335 in | 19.793 – 19.935 mm0.7793 – 0.7848 in | 18.631 – 19.172 mm0.7335 – 0.7548 in | 19.651 – 19.793 mm0.7737 – 0.7793 in | 19.509 – 19.793 mm0.7681 – 0.7793 in | 20.671 – 20.955 mm0.8138 – 0.8250 in |
| 5/8 | 14 | 1.814 mm0.0714 in | 22.911 mm0.9020 in | 21.749 mm0.8563 in | 20.587 mm0.8105 in | 21.749 – 21.891 mm0.8563 – 0.8619 in | 20.587 – 21.128 mm0.8105 – 0.8318 in | 21.607 – 21.749 mm0.8507 – 0.8563 in | 21.465 – 21.749 mm0.8451 – 0.8563 in | 22.627 – 22.911 mm0.8908 – 0.9020 in |
| 3/4 | 14 | 1.814 mm0.0714 in | 26.441 mm1.0410 in | 25.279 mm0.9952 in | 24.117 mm0.9495 in | 25.279 – 25.421 mm0.9952 – 1.0008 in | 24.117 – 24.658 mm0.9495 – 0.9708 in | 25.137 – 25.279 mm0.9896 – 0.9952 in | 24.995 – 25.279 mm0.9841 – 0.9952 in | 26.157 – 26.441 mm1.0298 – 1.0410 in |
| 7/8 | 14 | 1.814 mm0.0714 in | 30.201 mm1.1890 in | 29.039 mm1.1433 in | 27.877 mm1.0975 in | 29.039 – 29.181 mm1.1433 – 1.1489 in | 27.877 – 28.418 mm1.0975 – 1.1188 in | 28.897 – 29.039 mm1.1377 – 1.1433 in | 28.755 – 29.039 mm1.1321 – 1.1433 in | 29.917 – 30.201 mm1.1778 – 1.1890 in |
| 1 | 11 | 2.309 mm0.0909 in | 33.249 mm1.3090 in | 31.770 mm1.2508 in | 30.291 mm1.1926 in | 31.770 – 31.950 mm1.2508 – 1.2579 in | 30.291 – 30.931 mm1.1926 – 1.2178 in | 31.590 – 31.770 mm1.2437 – 1.2508 in | 31.410 – 31.770 mm1.2366 – 1.2508 in | 32.889 – 33.249 mm1.2948 – 1.3090 in |
| 1 1/8 | 11 | 2.309 mm0.0909 in | 37.897 mm1.4920 in | 36.418 mm1.4338 in | 34.939 mm1.3756 in | 36.418 – 36.598 mm1.4338 – 1.4409 in | 34.939 – 35.579 mm1.3756 – 1.4007 in | 36.238 – 36.418 mm1.4267 – 1.4338 in | 36.058 – 36.418 mm1.4196 – 1.4338 in | 37.537 – 37.897 mm1.4778 – 1.4920 in |
| 1 1/4 | 11 | 2.309 mm0.0909 in | 41.910 mm1.6500 in | 40.431 mm1.5918 in | 38.952 mm1.5335 in | 40.431 – 40.611 mm1.5918 – 1.5989 in | 38.952 – 39.592 mm1.5335 – 1.5587 in | 40.251 – 40.431 mm1.5847 – 1.5918 in | 40.071 – 40.431 mm1.5776 – 1.5918 in | 41.550 – 41.910 mm1.6358 – 1.6500 in |
| 1 1/2 | 11 | 2.309 mm0.0909 in | 47.803 mm1.8820 in | 46.324 mm1.8238 in | 44.845 mm1.7656 in | 46.324 – 46.504 mm1.8238 – 1.8309 in | 44.845 – 45.485 mm1.7656 – 1.7907 in | 46.144 – 46.324 mm1.8167 – 1.8238 in | 45.964 – 46.324 mm1.8096 – 1.8238 in | 47.443 – 47.803 mm1.8678 – 1.8820 in |
| 1 3/4 | 11 | 2.309 mm0.0909 in | 53.746 mm2.1160 in | 52.267 mm2.0578 in | 50.788 mm1.9995 in | 52.267 – 52.447 mm2.0578 – 2.0648 in | 50.788 – 51.428 mm1.9995 – 2.0247 in | 52.087 – 52.267 mm2.0507 – 2.0578 in | 51.907 – 52.267 mm2.0436 – 2.0578 in | 53.386 – 53.746 mm2.1018 – 2.1160 in |
| 2 | 11 | 2.309 mm0.0909 in | 59.614 mm2.3470 in | 58.135 mm2.2888 in | 56.656 mm2.2306 in | 58.135 – 58.315 mm2.2888 – 2.2959 in | 56.656 – 57.296 mm2.2306 – 2.2557 in | 57.955 – 58.135 mm2.2817 – 2.2888 in | 57.775 – 58.135 mm2.2746 – 2.2888 in | 59.254 – 59.614 mm2.3328 – 2.3470 in |
| Size | TPI | Pitch | Pipe OD, D | E0 | E1 | L1 | L2 | Thread height |
|---|---|---|---|---|---|---|---|---|
| 1/16 | 27 | 0.03704 in0.941 mm | 0.3125 in7.938 mm | 0.27118 in6.888 mm | 0.28118 in7.142 mm | 0.160 in4.06 mm4.32 threads | 0.2611 in6.63 mm | 0.02963 in0.753 mm |
| 1/8 | 27 | 0.03704 in0.941 mm | 0.405 in10.287 mm | 0.36351 in9.233 mm | 0.37360 in9.489 mm | 0.1615 in4.10 mm4.36 threads | 0.2639 in6.70 mm | 0.02963 in0.753 mm |
| 1/4 | 18 | 0.05556 in1.411 mm | 0.540 in13.716 mm | 0.47739 in12.126 mm | 0.49163 in12.487 mm | 0.2278 in5.79 mm4.10 threads | 0.4018 in10.21 mm | 0.04444 in1.129 mm |
| 3/8 | 18 | 0.05556 in1.411 mm | 0.675 in17.145 mm | 0.61201 in15.545 mm | 0.62701 in15.926 mm | 0.240 in6.10 mm4.32 threads | 0.4078 in10.36 mm | 0.04444 in1.129 mm |
| 1/2 | 14 | 0.07143 in1.814 mm | 0.840 in21.336 mm | 0.75843 in19.264 mm | 0.77843 in19.772 mm | 0.320 in8.13 mm4.48 threads | 0.5337 in13.56 mm | 0.05714 in1.451 mm |
| 3/4 | 14 | 0.07143 in1.814 mm | 1.050 in26.670 mm | 0.96768 in24.579 mm | 0.98887 in25.117 mm | 0.339 in8.61 mm4.75 threads | 0.5457 in13.86 mm | 0.05714 in1.451 mm |
| 1 | 11.5 | 0.08696 in2.209 mm | 1.315 in33.401 mm | 1.21363 in30.826 mm | 1.23863 in31.461 mm | 0.400 in10.16 mm4.60 threads | 0.6828 in17.34 mm | 0.06957 in1.767 mm |
| 1 1/4 | 11.5 | 0.08696 in2.209 mm | 1.660 in42.164 mm | 1.55713 in39.551 mm | 1.58338 in40.218 mm | 0.420 in10.67 mm4.83 threads | 0.7068 in17.95 mm | 0.06957 in1.767 mm |
| 1 1/2 | 11.5 | 0.08696 in2.209 mm | 1.900 in48.260 mm | 1.79609 in45.621 mm | 1.82234 in46.287 mm | 0.420 in10.67 mm4.83 threads | 0.7235 in18.38 mm | 0.06957 in1.767 mm |
| 2 | 11.5 | 0.08696 in2.209 mm | 2.375 in60.325 mm | 2.26902 in57.633 mm | 2.29627 in58.325 mm | 0.436 in11.07 mm5.01 threads | 0.7565 in19.22 mm | 0.06957 in1.767 mm |
Compiled from published references for ISO 965-1 and -2 (metric), ISO 7-1 (R, Rc, Rp), ISO 228-1 (G) and ASME B1.20.1 (NPT), checked against each other. Where references disagreed, we checked the numbers against the standard formulas and used the consistent value.
This is general information, not engineering advice. Thread standards are revised; check the edition named on your drawing, and confirm gauging requirements with your own quality department.
If you are sourcing a turned part with these threads, send the drawing.
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