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 5996-01-630-1611
NSN 5998-00-347-9473
NSN 6610-01-160-6585
NSN 5925-01-388-7049
NSN 5915-01-130-0310
NSN 5975-01-461-7456
NSN 5985-00-216-8064
NSN 5998-01-161-6171
NSN 5965-00-067-0290
NSN 4140-00-252-0879
NSN 6135-01-383-0151
NSN 6130-01-645-3774