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 5905-00-554-4325
NSN 6320-01-029-4220
NSN 6645-00-982-7204
NSN 6105-01-413-9134
NSN 5975-00-404-7476
NSN 5915-01-506-9829
NSN 5960-00-840-7103
NSN 5910-00-269-4755
NSN 6135-01-184-0727
NSN 5975-01-570-4407
NSN 5990-01-115-5859
NSN 5905-01-536-3340