| American Standard Taper Pipe External Thread | ||||
| Nominal size | Actual OD |
Threads per inch |
Length of engagement (tightened by hand) | Length of effective thread |
| 1/8 | 0.407 | 27 | 0.124≈3.3turns | 0.26 |
| 1/4 | 0.546 | 18 | 0.172≈3.1turns | 0.401 |
| 3/8 | 0.681 | 18 | 0.184≈3.3turns | 0.408 |
| 1/2 | 0.85 | 14 | 0.248≈3.4turns | 0.534 |
| 3/4 | 1.06 | 14 | 0.267≈3.7turns | 0.546 |