Thread Identification Guide - Home | Trausch Dynamics
https://www.hydraulicstore.com/images/pdf/NPSM%20THREAD.pdf
WebNPSM. NPTF, BSPT and BSPP measure 1/4” larger than their actual size. For example, a 1/4” NPTF, BSPT or BSPP will actually measure 1/2” on the O. D. of the . threads. JIC, SAE O-ring & Flat Face threads measure as listed below. The first number listed is the size of thread, the second number is the threads per inch.
DA: 27 PA: 100 MOZ Rank: 100