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What is NPTF thread

2022-10-11 Page view : 6 views

NPTF, American dry seal conical Pipe Thread, short for National (American) Pipe Thread, belongs to the United States standard 60 degree conical Pipe Thread, used in North America.

The tooth shape Angle is 60 degrees, the taper is 1:16, and the taper limit deviation is -0.005~+0.005mm/mm.

National standard can refer to GB/T 12716-2011 60° sealing pipe thread.

NPTF threads are of two grades: Grade 1 and Grade 2. For grade 2 threads, check the cutting height of the thread. Level 1 can be omitted.
We are NPTF threads manufacturer.
When testing the NPTF external thread, use L1 ring gauge and L2 ring gauge at the same time; To test the internal thread of NPTF, both L1 plug gauge and L3 plug gauge should be used. The difference between the measured value obtained by L2 and L3 and the measured value obtained by L1 shall not exceed half buckle (-0.5P~+0.5P).

NPTF thread working characteristics:
The precision of NPTF dry seal pipe thread is higher than that of NPT thread. It does not need any packing when screwing, and completely depends on the thread itself to form a seal. There is no sealing medium between the threads. Dry seal pipe threads have strict tolerances. They are precision threads and are only used in special situations. This thread has high strength and good sealing property, and can be used in brittle and hard materials with thin cross section to reduce fracture phenomenon. NPTF internal and external threads have no gap between the top and the bottom, which is an interference fit, while NPT thread is a transition fit. NPTF threads are mainly used in high temperature and high pressure places with strict sealing requirements.

Note: NPTF taps are acceptable for NPT threads, but NPT taps should not be used for NPTF threads because they produce threads that leak. NPT has both right-handed and left-handed threads, while NPTF has only one right-handed thread.