Table of basic dimensions for pipe threads
Unit: mm
| Dimension code | Number of teeth per 25.4 mm, n | Step, p. | Tooth height, h | Approximate arc radius, r≈ | Basic Diameter in Datum | Reference distance | Effective thread length | ||
| Main diameter (reference diameter), d=D | Median Diameter, d2=D2 | Smallest Diameter, d1=D1 | |||||||
| 01/16 | 28 | 0.907 | 0.581 | 0.125 | 7,723 | 7,142 | 6,561 | 4.0 | 6.5 |
| 1/8 | 28 | 0.907 | 0.581 | 0.125 | 9,728 | 9,147 | 8,566 | 4.0 | 6.5 |
| 1/4 | 19 | 1,337 | 0.586 | 0.184 | 13,157 | 12,301 | 11,445 | 6.0 | 9.7 |
| 3/8 | 19 | 1,337 | 0.586 | 0.184 | 16,662 | 15,806 | 14,950 | 6.4 | 10.1 |
| 1/2 | 14 | 1,814 | 1,162 | 0.249 | 20,955 | 19,793 | 18,631 | 8.2 | 13.2 |
| 3/4 | 14 | 1,814 | 1,162 | 0.249 | 26,441 | 25,279 | 24,117 | 9.5 | 14.5 |
| 1 | 11 | 2,309 | 1,479 | 0.317 | 33,249 | 31,770 | 30,291 | 10.4 | 16.8 |
| 1.1/4 | 11 | 2,309 | 1,479 | 0.317 | 41,910 | 40,431 | 38,952 | 12.7 | 19.1 |
| 1.1/2 | 11 | 2,309 | 1,479 | 0.317 | 47,803 | 46,324 | 44,845 | 12.7 | 19.1 |
| two | 11 | 2,309 | 1,479 | 0.317 | 59,614 | 58,135 | 56,656 | 15.9 | 23.4 |
| 2.1/2 | 11 | 2,309 | 1,479 | 0.317 | 75,184 | 73,705 | 72,226 | 17.5 | 26.7 |
| 3 | 11 | 2,309 | 1,479 | 0.317 | 87,884 | 86,405 | 84,926 | 20.6 | 29.8 |
| 3.1/2 | 11 | 2,309 | 1,479 | 0.317 | 100,330 | 98,851 | 97,372 | 22.2 | 31.4 |
| 4 | 11 | 2,309 | 1,479 | 0.317 | 113,030 | 111,551 | 110,072 | 25.4 | 35.8 |
| 5 | 11 | 2,309 | 1,479 | 0.317 | 138,430 | 136,951 | 135,472 | 28.6 | 40.1 |
| 6 | 11 | 2,309 | 1,479 | 0.317 | 163,830 | 162,351 | 160,872 | 28.6 | 40.1 |
Table of basic dimensions for tapered pipe threads
| Dimension code | Number of teeth per 25.4 mm, n | Basic Diameter in Datum | Reference distance | ||
| Main diameter (reference diameter), d=D | Median Diameter, d2=D2 | Smallest Diameter, d1=D1 | |||
| 01/16 | 27 | 7,895 | 7,142 | 6,389 | 4,064 |
| 1/8 | 27 | 10,242 | 9,489 | 8,736 | 4,102 |
| 1/4 | 18 | 13,616 | 12,487 | 11,358 | 5,786 |
| 3/8 | 18 | 17,055 | 15,926 | 14,797 | 6,096 |
| 1/2 | 14 | 21,223 | 19,772 | 18,321 | 8,128 |
| 3/4 | 14 | 26,568 | 25,117 | 23,666 | 8,611 |
| 1 | 11.5 | 33,228 | 31,461 | 29,694 | 10,160 |
| 1.1/4 | 11.5 | 41,985 | 40,218 | 38,451 | 10,668 |
| 1.1/2 | 11.5 | 48,054 | 46,287 | 44,520 | 10,668 |
| two | 11.5 | 60,092 | 58,325 | 56,558 | 11,074 |
| 2.1/2 | 8 | 72,699 | 70,159 | 67,619 | 17,323 |
| 3 | 8 | 88,608 | 86,068 | 83,528 | 19,456 |
| 3.1/2 | 8 | 101,316 | 98,776 | 96,236 | 20,853 |
| 4 | 8 | 113,973 | 111,433 | 108,893 | 21,438 |
