ASME B1.20.1-1983/ANSI Pipe Threads, General Purpose (Inch)

An American National Standard. The American Society of Mechanical Engineers (ASME). Revision of ANSI B2.1-1968. Date of Issuance: Augustl 31,1983. 32 p. This American National Standard covers dimensions and gaging of pipe threads for general purpose applications.
The types of pipe threads included in this Standard are designated by specifying in sequence the nominal pipe size,' number of threads per inch and the thread series symbol as follows:
3/8 - 18 NPT
1/2 - 14 NPTR
1/8 - 27 NPSM
1/8 - 27 NPSL
1/8 - 27 NPSC
1 -11.5NPSH