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 5910-00-916-8071
NSN 6110-01-444-3302
NSN 5915-01-049-5027
NSN 6610-00-224-8821
NSN 6650-01-631-3027
NSN 6145-00-860-3475
NSN 6110-01-327-7386
NSN 6685-01-626-4601
NSN 6130-00-518-1884
NSN 5985-00-452-0157
NSN 6645-00-243-9470
NSN 6685-01-406-5348