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 5965-01-227-3705
NSN 5835-00-491-3834
NSN 5990-01-172-4553
NSN 6320-01-442-8604
NSN 2925-01-424-0235
NSN 6685-01-408-0860
NSN 5960-01-021-3712
NSN 5998-00-358-5654
NSN 5895-01-440-9847
NSN 6620-01-386-5914
NSN 6620-01-152-4099
NSN 6150-00-284-2976