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 5965-00-755-4657
NSN 5855-00-631-4565
NSN 6150-01-068-0671
NSN 6130-00-394-3421
NSN 6610-01-413-3912
NSN 6650-01-462-5879
NSN 5935-01-182-1779
NSN 6240-00-660-8849
NSN 5945-01-596-7506
NSN 5998-00-450-0181
NSN 5965-01-253-5353
NSN 6105-00-120-9601