National Taper Pipe Thread ASE B1.20.1
| DN | Threads Per Inch |
Pith of thread | Thread length | DIA. At Reference Surface | Boot DIA, of the pipe thread | Height | ||||
| in | mm | n | p | L1 | L2 | d | d1 | d2 | d T | h1 |
| 3/8 | 10 | 18 | 1.411 | 10.5 | 6.096 | 17.055 | 15.926 | 14.797 | 14.416 | 1.129 |
| 1/2 | 15 | 14 | 1.814 | 13.5 | 8.128 | 21.223 | 19.772 | 18.321 | 17.813 | 1.451 |
| 3/4 | 20 | 14 | 1.814 | 14 | 8.611 | 26.568 | 25.117 | 23.666 | 23.128 | 1.485 |
| 1 | 25 | 11-1/2 | 2.209 | 17.5 | 10.160 | 33.228 | 31.461 | 29.694 | 29.059 | 1.767 |
| 1-1/4 | 32 | 11-1/2 | 2.209 | 18 | 10.668 | 41.985 | 40.218 | 38.451 | 37.784 | 1.767 |
| 1-1/2 | 40 | 11-1/2 | 2.209 | 18.5 | 10.668 | 48.054 | 46.287 | 44.520 | 43.853 | 1.767 |
| 2 | 50 | 11-1/2 | 2.209 | 19 | 11.074 | 60.092 | 58.325 | 56.558 | 55.866 | 1.767 |
