Pipe end has an insert in it
A fitting that forms an angle of less than 180 degrees (3.142 radians) from the straight flow. One connecting end has standard pipe threads, or is unthreaded and designed to accommodate a pipe. The other end has 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; elbow, tube; and connector, multiple, fluid pressure line.
Classification: Threaded elbows and bends of iron or steel (other than cast iron or stainless steel) for pipes and tubes
NSN 5905-00-022-9744
NSN 6240-00-908-5069
NSN 5975-01-102-4084
NSN 5996-00-132-4203
NSN 5960-00-232-2512
NSN 5920-00-916-7018
NSN 5985-00-499-9147
NSN 5950-01-659-1815
NSN 6320-01-246-4390
NSN 5905-01-164-6299
NSN 5895-01-466-4780
NSN 2925-00-066-4253