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 5999-01-502-4290
NSN 6220-01-436-7131
NSN 6130-00-283-4329
NSN 2925-01-419-3805
NSN 6650-01-425-1600
NSN 5975-00-108-6464
NSN 5935-01-359-9540
NSN 6135-00-255-1340
NSN 4140-01-655-9148
NSN 5965-01-221-8182
NSN 5950-01-238-5791
NSN 6620-01-367-2597