The difference between NPT and NPTF threads is that NPTF pipe fittings do not require additional sealants such as hemp or Teflon tape. Due to the conical arrangement of the thread, it is self-sealing. Visually, it is difficult to distinguish between the two types of thread; this is only possible by precise measurement.
Thread Sizes |
Thread Pitch (mm) |
Outer Diameter (mm) |
Core Hole Diameter (mm) |
Gear number pro Inch |
NPTF 1/16" | 0,941 | 7,90 | 6,15 | 27 |
NPTF 1/8" | 0,941 | 10,24 | 8,40 | 27 |
NPTF 1/4" | 1,411 | 13,62 | 11,00 | 18 |
NPTF 3/8" | 1,411 | 17,06 | 14,50 | 18 |
NPTF 1/2" | 1,814 | 21,22 | 17,75 | 14 |
NPTF 3/4" | 1,814 | 26,57 | 23,00 | 14 |
NPTF 1" | 2,209 | 33,23 | 29,00 | 11,5 |
NPTF 1 1/4" | 2,209 | 41,99 | 37,50 | 11,5 |
NPTF 1 1/2" | 2,209 | 48,05 | 44,00 | 11,5 |
NPTF 2" | 2,209 | 60,09 | 56,00 | 11,5 |
NPTF 2 1/2" | 3,175 | 72,70 | 66,50 | 8 |
NPTF 3" | 3,175 | 88,61 | 82,50 | 8 |
* All information without guarantee.
Tip !
Pipe thread Sealing cord or sealing tape.