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 5930-01-439-9922
NSN 2925-00-120-9302
NSN 5996-00-940-8927
NSN 6685-01-056-7360
NSN 6645-01-442-0466
NSN 5999-00-679-9934
NSN 5895-01-307-6350
NSN 6105-01-431-8998
NSN 5960-01-108-6636
NSN 5910-01-631-0397
NSN 6145-01-255-6631
NSN 6650-01-479-5386