Tapered thread for pipes

Tapered pipe threads (pipe tapered threads) are sealed threads and are functionally designed to prevent leakage. However, in order to completely prevent leakage, anti-leak tape or sealant is usually wrapped around the surface of the thread. The thread mountain shape is rounded, and the tooth mountain angle is 55°, distributed in the taper On 1/16 tapered pipes, in the ISO 7-1 standard, the male thread is marked R and the female thread is marked Rc. German DIN 2999, Japanese JIS B 0203, British BSP Tr and other standards are set with reference to ISO 7-1. PT is the specification name of the old JIS standard. Simply put, R = PT = BSPT.

The angle and shape of the tapered thread for pipes are the same as those of the parallel thread G(PF) for pipes, so it is practically feasible to use G(PF) female threads with R(PT) male threads. The angle between the peak and the mountain of NPT tapered threads for pipes made in the United States is different from that of tapered threads for pipes. R(PT) thread, cannot be mixed.

Thread representation
R [referred to as diameter]
Pipe tapered thread R, PT, BSPT

Unit mm

* Base length: Since the thread diameter on the cone surface will change with position, an imaginary base plane is defined as a reference for the major diameter, middle diameter, and minor diameter. The distance between this surface and the external thread end face is called Datum length.