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 4140-01-606-4573
NSN 5990-00-226-1152
NSN 5965-01-618-6567
NSN 6320-01-166-3602
NSN 5985-01-094-5647
NSN 5998-01-584-5338
NSN 5920-01-036-9781
NSN 5990-01-151-8756
NSN 4140-00-193-0067
NSN 2925-00-275-1807
NSN 5965-00-949-5765
NSN 6145-00-539-9799