Second end has a groove at end before threads
A fitting that forms an angle of less that 180 degrees (3.141 radians) from a straight flow. One connecting 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. The other end has external or internal machine threads (straight threads other than pipe or hose series) and is designed to facilitate a gasket, preformed packing, washer, or the like, to form a seal at the boss. It may have side or heel inlet(s). It is designed to connect a tube or tube fitting to a boss or boss fitting on items such as tanks, housings, valve fittings, or the like.
Classification: Threaded elbows and bends of iron or steel (other than cast iron or stainless steel) for pipes and tubes
NSN 5925-00-468-2757
NSN 5950-01-457-4085
NSN 4140-01-614-5630
NSN 5930-01-425-1902
NSN 6150-00-633-7160
NSN 5965-01-016-8491
NSN 5975-01-459-8112
NSN 5905-01-648-0238
NSN 5920-01-616-4255
NSN 6145-00-099-8986
NSN 6220-01-285-0199
NSN 5945-00-239-7558