主要依据:ANSI/ASME B1.1和B1.3M
典型外螺纹基本尺寸
| 螺纹规格 | 螺纹精度等级 | 基本尺寸 | 小径 | 中径 | 大径 | ||
| 最小 | 最大 | 最小 | 最大 | 最小 | |||
| 0-80 | 2B | 0.0600 | 0.0465 | 0.0514 | 0.0519 | 0.0542 | 0.0600 |
| 0-80 | 3B | 0.0600 | 0.0465 | 0.0514 | 0.0519 | 0.0536 | 0.0600 |
| 1-64 | 2B | 0.0730 | 0.0561 | 0.0623 | 0.0629 | 0.0655 | 0.0730 |
| 1-64 | 3B | 0.0730 | 0.0561 | 0.0623 | 0.0629 | 0.0648 | 0.0730 |
| 1-72 | 2B | 0.0730 | 0.0580 | 0.0635 | 0.0640 | 0.0665 | 0.0730 |
| 1-72 | 3B | 0.0730 | 0.0580 | 0.0635 | 0.0640 | 0.0659 | 0.0730 |
| 2-56 | 2B | 0.0860 | 0.0667 | 0.0737 | 0.0744 | 0.0772 | 0.0860 |
| 2-56 | 3B | 0.0860 | 0.0667 | 0.0737 | 0.0744 | 0.0765 | 0.0860 |
| 2-64 | 2B | 0.0860 | 0.0691 | 0.0753 | 0.0759 | 0.0786 | 0.0860 |
| 2-64 | 3B | 0.0860 | 0.0691 | 0.0753 | 0.0759 | 0.0779 | 0.0860 |
| 3-48 | 2B | 0.0990 | 0.0764 | 0.0845 | 0.0855 | 0.0885 | 0.0990 |
| 3-48 | 3B | 0.0990 | 0.0764 | 0.0845 | 0.0855 | 0.0877 | 0.0990 |
| 3-56 | 2B | 0.0990 | 0.0797 | 0.0865 | 0.0874 | 0.0902 | 0.0990 |
| 3-56 | 3B | 0.0990 | 0.0797 | 0.0865 | 0.0874 | 0.0895 | 0.0990 |
| 4-40 | 2B | 0.1120 | 0.0849 | 0.0939 | 0.0958 | 0.0991 | 0.1120 |
| 4-40 | 3B | 0.1120 | 0.0849 | 0.0939 | 0.0958 | 0.0982 | 0.1120 |
| 4-48 | 2B | 0.1120 | 0.0894 | 0.0968 | 0.0985 | 0.1016 | 0.1120 |
| 4-48 | 3B | 0.1120 | 0.0894 | 0.0968 | 0.0985 | 0.1008 | 0.1120 |
| 5-40 | 2B | 0.1250 | 0.0979 | 0.1062 | 0.1088 | 0.1121 | 0.1250 |
| 5-40 | 3B | 0.1250 | 0.0979 | 0.1062 | 0.1088 | 0.1113 | 0.1250 |
| 5-44 | 2B | 0.1250 | 0.1004 | 0.1079 | 0.1102 | 0.1134 | 0.1250 |
| 5-44 | 3B | 0.1250 | 0.1004 | 0.1079 | 0.1102 | 0.1126 | 0.1250 |
| 6-32 | 2B | 0.1380 | 0.1040 | 0.1140 | 0.1177 | 0.1214 | 0.1380 |
| 6-32 | 3B | 0.1380 | 0.1040 | 0.1140 | 0.1177 | 0.1204 | 0.1380 |
| 6-40 | 2B | 0.1380 | 0.1110 | 0.119 | 0.1218 | 0.1252 | 0.1380 |
| 6-40 | 3B | 0.1380 | 0.1110 | 0.1186 | 0.1218 | 0.1243 | 0.1380 |
| 8-32 | 2B | 0.1640 | 0.1300 | 0.139 | 0.1437 | 0.1475 | 0.1640 |
| 8-32 | 3B | 0.1640 | 0.1300 | 0.1389 | 0.1437 | 0.1465 | 0.1640 |
| 8-36 | 2B | 0.1640 | 0.1340 | 0.142 | 0.1460 | 0.1496 | 0.1640 |
| 8-36 | 3B | 0.1640 | 0.1340 | 0.1416 | 0.1460 | 0.1487 | 0.1640 |
| 10-24 | 2B | 0.1900 | 0.1450 | 0.1560 | 0.1629 | 0.1672 | 0.1900 |
| 10-24 | 3B | 0.1900 | 0.1450 | 0.1555 | 0.1629 | 0.1661 | 0.1900 |
| 10-32 | 2B | 0.1900 | 0.1560 | 0.1640 | 0.1697 | 0.1736 | 0.1900 |
| 10-32 | 3B | 0.1900 | 0.1560 | 0.1641 | 0.1697 | 0.1726 | 0.1900 |
| 1/4-20 | 2B | 0.2500 | 0.1960 | 0.2070 | 0.2175 | 0.2248 | 0.2500 |
| 1/4-20 | 3B | 0.2500 | 0.1960 | 0.2070 | 0.2175 | 0.220 | 0.2500 |
| 1/4-28 | 2B | 0.2500 | 0.2110 | 0.220 | 0.2268 | 0.2311 | 0.2500 |
| 1/4-28 | 3B | 0.2500 | 0.2110 | 0.2190 | 0.2268 | 0.2300 | 0.2500 |
| 5/16-18 | 2B | 0.3125 | 0.2520 | 0.265 | 0.2764 | 0.2817 | 0.3125 |
| 5/16-18 | 3B | 0.3125 | 0.2520 | 0.2630 | 0.2764 | 0.2803 | 0.3125 |
| 5/16-24 | 2B | 0.3125 | 0.2670 | 0.277 | 0.2854 | 0.2902 | 0.3125 |
| 5/16-24 | 3B | 0.3125 | 0.2670 | 0.2754 | 0.2854 | 0.2890 | 0.3125 |
| 3/8-16 | 2B | 0.3750 | 0.3070 | 0.321 | 0.3344 | 0.3401 | 0.3750 |
| 3/8-16 | 3B | 0.3750 | 0.3070 | 0.3182 | 0.3344 | 0.3387 | 0.3750 |
| 3/8-24 | 2B | 0.3750 | 0.3300 | 0.340 | 0.3479 | 0.3528 | 0.3750 |
| 3/8-24 | 3B | 0.3750 | 0.3300 | 0.3372 | 0.3479 | 0.3516 | 0.3750 |
| 7/16-14 | 2B | 0.4375 | 0.3600 | 0.376 | 0.3911 | 0.3972 | 0.4375 |
| 7/16-14 | 3B | 0.4375 | 0.3600 | 0.3717 | 0.3911 | 0.3957 | 0.4375 |
| 7/16-20 | 2B | 0.4375 | 0.3830 | 0.395 | 0.4050 | 0.4104 | 0.4375 |
| 7/16-20 | 3B | 0.4375 | 0.3830 | 0.3916 | 0.4050 | 0.4091 | 0.4375 |
| 1/2-13 | 2B | 0.5000 | 0.4170 | 0.434 | 0.4500 | 0.4565 | 0.5000 |
| 1/2-13 | 3B | 0.5000 | 0.4170 | 0.4284 | 0.4500 | 0.4548 | 0.5000 |
| 1/2-20 | 2B | 0.5000 | 0.4460 | 0.457 | 0.4675 | 0.4731 | 0.5000 |
| 1/2-20 | 3B | 0.5000 | 0.4460 | 0.4537 | 0.4675 | 0.4717 | 0.5000 |
| 9/16-12 | 2B | 0.5625 | 0.4720 | 0.4900 | 0.5084 | 0.5152 | 0.5625 |
| 9/16-12 | 3B | 0.5625 | 0.4720 | 0.4843 | 0.5084 | 0.5135 | 0.5625 |
| 9/16-14 | 2B | 0.5625 | 0.4850 | 0.5010 | 0.5161 | 0.5226 | 0.5625 |
| 9/16-16 | 2B | 0.5625 | 0.4950 | 0.5090 | 0.5219 | 0.5280 | 0.5625 |
| 9/16-16 | 3B | 0.5625 | 0.4950 | 0.5040 | 0.5219 | 0.5265 | 0.5625 |
| 9/16-18 | 2B | 0.5625 | 0.5020 | 0.5150 | 0.5264 | 0.5323 | 0.5625 |
| 9/16-18 | 3B | 0.5625 | 0.5020 | 0.5106 | 0.5264 | 0.5308 | 0.5625 |
| 9/16-20 | 2B | 0.5625 | 0.5080 | 0.5200 | 0.5300 | 0.5355 | 0.5625 |
| 9/16-20 | 3B | 0.5625 | 0.5080 | 0.5162 | 0.5300 | 0.5341 | 0.5625 |
| 9/16-24 | 2B | 0.5625 | 0.5170 | 0.5270 | 0.5354 | 0.5404 | 0.5625 |
| 9/16-24 | 3B | 0.5625 | 0.5170 | 0.5244 | 0.5354 | 0.5392 | 0.5625 |
| 9/16-32 | 2B | 0.5625 | 0.5290 | 0.5360 | 0.5422 | 0.5467 | 0.5625 |
| 9/16-32 | 3B | 0.5625 | 0.5290 | 0.5344 | 0.5422 | 0.5456 | 0.5625 |
| 5/8-11 | 2B | 0.6250 | 0.5270 | 0.546 | 0.5660 | 0.5732 | 0.6250 |
| 5/8-11 | 3B | 0.6250 | 0.5270 | 0.5391 | 0.5660 | 0.5714 | 0.6250 |
| 5/8-18 | 2B | 0.6250 | 0.5650 | 0.578 | 0.5889 | 0.5949 | 0.6250 |
| 5/8-18 | 3B | 0.6250 | 0.5650 | 0.5730 | 0.5889 | 0.5934 | 0.6250 |
| 3/4-10 | 2B | 0.7500 | 0.6420 | 0.663 | 0.6850 | 0.6927 | 0.7500 |
| 3/4-10 | 3B | 0.7500 | 0.6420 | 0.6545 | 0.6850 | 0.6907 | 0.7500 |
| 3/4-16 | 2B | 0.7500 | 0.6820 | 0.696 | 0.7094 | 0.7159 | 0.7500 |
| 3/4-16 | 3B | 0.7500 | 0.6820 | 0.6908 | 0.7094 | 0.7143 | 0.7500 |
| 7/8 -9 | 2B | 0.8750 | 0.7550 | 0.778 | 0.8028 | 0.8110 | 0.8750 |
| 7/8 -9 | 3B | 0.8750 | 0.7550 | 0.7681 | 0.8028 | 0.8089 | 0.8750 |
| 7/8-14 | 2B | 0.8750 | 0.7980 | 0.814 | 0.8286 | 0.8356 | 0.8750 |
| 7/8-14 | 3B | 0.8750 | 0.7980 | 0.8068 | 0.8286 | 0.8339 | 0.8750 |
| 1 -8 | 2B | 1.0000 | 0.8650 | 0.890 | 0.9188 | 0.9276 | 1.0000 |
| 1 -8 | 3B | 1.0000 | 0.8650 | 0.8797 | 0.9188 | 0.9254 | 1.0000 |
| 1 -12 | 2B | 1.0000 | 0.9100 | 0.928 | 0.9459 | 0.9535 | 1.0000 |
| 1 -12 | 3B | 1.0000 | 0.9100 | 0.9198 | 0.9459 | 0.9516 | 1.0000 |
| 1 1/8-7 | 2B | 1.1250 | 0.9700 | 0.998 | 1.0322 | 1.0416 | 1.1250 |
| 1 1/8-12 | 2B | 1.1250 | 1.0350 | 1.053 | 1.0709 | 1.0787 | 1.1250 |
| 1 1/4-7 | 2B | 1.2500 | 1.0950 | 1.123 | 1.1572 | 1.1668 | 1.2500 |
| 1 1/4-12 | 2B | 1.2500 | 1.1600 | 1.178 | 1.1959 | 1.2039 | 1.2500 |
| 1 3/8-6 | 2B | 1.3750 | 1.1950 | 1.225 | 1.2667 | 1.2771 | 1.3750 |
| 1 3/8-12 | 2B | 1.3750 | 1.2850 | 1.303 | 1.3209 | 1.3291 | 1.3750 |
| 1 1/2-6 | 2B | 1.5000 | 1.3200 | 1.350 | 1.3917 | 1.4022 | 1.5000 |
| 1 1/2-12 | 2B | 1.5000 | 1.4100 | 1.428 | 1.4459 | 1.4542 | 1.5000 |
| 1 3/4-5 | 2B | 1.7500 | 1.5340 | 1.568 | 1.6201 | 1.6317 | 1.7500 |
| 2 -6 | 2B | 2.0000 | 1.820 | 1.850 | 1.8917 | 1.9028 | 2.0000 |
