Special o-ring material, per mil-p-5510c, do not dupe to any other nsn
An adapter having machine threads (straight threads other than pipe or hose series) designed to accommodate a tube on one end or an unthreaded end 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 is designed to join a tube or tube fitting to a boss or boss fitting in a straight line on items such as tanks, housings, valve fittings, and the like. See also coupling, tube and nipple, tube.
Classification: Other fittings nesoi of iron or nonalloy steel
NSN 5985-01-565-5451
NSN 5998-01-140-2630
NSN 6110-00-205-1778
NSN 5975-01-444-0599
NSN 6105-00-952-6547
NSN 5999-01-325-3581
NSN 5930-00-817-5482
NSN 7035-01-434-6134
NSN 5910-01-133-3897
NSN 5920-00-285-0903
NSN 5990-01-016-4194
NSN 5895-00-927-0912