The item is a flight safety critical aircraft part (fscap)
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: Threaded elbows and bends of iron or steel (other than cast iron or stainless steel) for pipes and tubes
NSN 6110-01-127-0461
NSN 6240-00-146-9322
NSN 4140-00-186-3062
NSN 5930-00-528-9728
NSN 6105-01-514-6197
NSN 6150-01-645-5659
NSN 5895-01-419-2045
NSN 6130-00-849-6298
NSN 5910-01-213-0761
NSN 5965-01-277-8589
NSN 6650-00-470-8594
NSN 6150-00-901-3200