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 6135-01-633-8502
NSN 5950-01-170-5893
NSN 5915-01-048-5420
NSN 6150-01-167-2982
NSN 5998-00-270-1179
NSN 6610-00-659-8760
NSN 5960-01-609-6565
NSN 6135-00-643-4843
NSN 6220-01-571-5721
NSN 6130-00-202-0027
NSN 6150-00-398-6527
NSN 5930-01-221-7938