The size is and for plumbing and heating
A fitting that forms an angle of less than 180 degrees (3.141 radians) from a straight flow. Both connecting ends have machine threads (straight threads other than pipe or hose series) designed to accommodate a tube or is unthreaded and designed to accommodate a tube. It may have side or heel inlet(s). See also elbow, pipe and connector, multiple, fluid pressure line.
Classification: Copper alloy tube or pipe fittings
NSN 5975-01-549-3561
NSN 6610-00-453-5163
NSN 5935-01-401-5324
NSN 4140-01-335-3451
NSN 6645-01-646-2953
NSN 5996-00-166-6442
NSN 7035-01-218-6960
NSN 5985-00-412-4394
NSN 5855-01-013-6864
NSN 5945-00-502-9644
NSN 5905-01-377-5273
NSN 5965-00-961-1627