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 6220-00-595-6954
NSN 6645-01-170-0341
NSN 5999-01-319-2322
NSN 6150-01-145-4449
NSN 5960-01-173-2338
NSN 6145-01-605-3228
NSN 5985-00-975-1893
NSN 6685-01-607-8180
NSN 2925-01-577-0004
NSN 6320-00-925-0558
NSN 5999-01-500-0364
NSN 6220-01-342-9961