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 6135-01-386-5709
NSN 2925-01-556-0333
NSN 6645-01-425-2330
NSN 5999-01-554-2818
NSN 5910-00-915-9247
NSN 6135-00-756-6149
NSN 5985-01-021-9578
NSN 6650-01-483-0938
NSN 6150-01-378-7494
NSN 4140-00-575-1161
NSN 5950-00-611-2601
NSN 5835-01-173-1578