The NPT pipe thread is a self-sealing thread with a flank angle of 60°, used for pressure-tight connections in pipeline systems.
Here you will find the dimensions of the self-sealing NPT pipe thread according to ANSI B 1.20.1-1983 with a flank angle of 60°.
Thread | Pitch | Diameter outside [mm] | Core hole diameter at the thin end of the pipe [mm] | Number of threads per 25.4 mm |
1/16“ – 27 NPT | 0.941 | 7.895 | 6.00 | 27 |
1/8“ – 27 NPT | 0.941 | 10.242 | 8.25 | 27 |
1/4“ – 18 NPT | 1.411 | 13.616 | 10.70 | 18 |
3/8“ – 18 NPT | 1.411 | 17.055 | 14.10 | 18 |
1/2“ – 14 NPT | 1.814 | 21.223 | 17.40 | 14 |
3/4“ – 14 NPT | 1.814 | 26.568 | 22.60 | 14 |
1“ – 11 1/2 NPT | 2.209 | 33.228 | 28.50 | 11.5 |
1 1/4“ – 11 1/2 NPT | 2.209 | 41.985 | 37.00 | 11.5 |
1 1/2“ – 11 1/2 NPT | 2.209 | 48.054 | 43.50 | 11.5 |
2“ – 11 1/2 NPT | 2.209 | 60.092 | 55.00 | 11.5 |
2 1/2“ – 8 NPT | 3.175 | 72.699 | 65.50 | 8 |
3“ – 8 NPT | 3.175 | 88.608 | 81.50 | 8 |
3 1/2“ – 8 NPT | 3.175 | 101.316 | 94.30 | 8 |
4“ – 8 NPT | 3.175 | 113.973 | 107.00 | 8 |
5“ – 8 NPT | 3.175 | 141.300 | 134.384 | 8 |
6“ – 8 NPT | 3.175 | 168.275 | 161.191 | 8 |
8“ – 8 NPT | 3.175 | 219.075 | 211.673 | 8 |
10“ – 8 NPT | 3.175 | 273.050 | 265.311 | 8 |
12“ – 8 NPT | 3.175 | 323.850 | 315.793 | 8 |
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