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 6685-01-653-6434
NSN 5990-00-813-9405
NSN 6685-01-145-3938
NSN 6145-00-932-1950
NSN 5910-00-717-0647
NSN 5999-00-816-7625
NSN 6240-01-376-0306
NSN 5905-00-476-6695
NSN 5835-00-170-5238
NSN 2925-00-149-0760
NSN 5965-00-959-4910
NSN 6135-00-078-9931