NPT Thread

NPT thread is a general-purpose American standard tapered pipe thread.

Among them, N stand for National (American) American national standard, P = PIPE, T = TAPER, and the tooth profile angle is 60°.

This type of pipe thread is commonly used in North America or is often seen using ANSI specifications.

PT Thread

PT thread is an imperial tapered thread with a thread angle of 55° and is most commonly used in sealing.
It is mostly used in European and Commonwealth countries.

In Taiwan, China, even Japan JIS standards also follow the imperial standard.