As differentiated by quality control iaw mil-q-9858
A fluid line fitting having a pipe, tube or hose connection or a through hole to accommodate a bolt, fluid passage on one end. The other end must have an external or internal thread for connecting a mating part to form a self-sealing coupling assembly. The fitting has either a self-sealing feature for the purpose of automatically shutting off the flow of fluid when disconnected from its mating half, or, if it has no self-sealing feature, is specifically designed to mate with a fitting with a self-sealing feature. For self-sealing fittings with a quick disconnect end, see coupling half, quick disconnect. For fluid line fittings without a self-sealing feature, see coupling (as modified).
NSN 5925-01-227-4631
NSN 5950-01-025-6732
NSN 5895-01-065-4445
NSN 6650-01-421-5355
NSN 5855-01-211-2437
NSN 5965-01-371-1297
NSN 6645-01-301-3066
NSN 5835-01-027-1828
NSN 6130-01-355-6083
NSN 5945-01-330-7147
NSN 6685-00-670-7708
NSN 5965-01-178-2367