NPT Taper Pipe Thread according ANSI B 1.20.1-1983
Here you finde the dimensions of the self-sealing NPT taper pipe thread according to ANSI B 1.20.1-1983 with a thread angle of 60°.
| Nominal size | Pitch | Major Diameter [mm] | Tapping Drill Size [mm] | Threads per inch (TPI) |
| 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 |
