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 6240-01-441-0027
NSN 6610-00-774-2680
NSN 5945-01-238-5542
NSN 6240-01-480-7820
NSN 5935-01-508-4046
NSN 5895-01-341-4962
NSN 4140-00-118-1816
NSN 5915-01-303-1384
NSN 6110-01-284-0318
NSN 4140-01-511-0286
NSN 5990-01-097-4721
NSN 5915-01-623-7594