A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6220-01-457-1204
NSN 5855-01-543-4274
NSN 6105-01-408-2661
NSN 5996-01-024-8898
NSN 6150-01-374-5498
NSN 6145-00-865-4833
NSN 6645-01-380-6111
NSN 5996-00-383-6173
NSN 5996-01-398-1632
NSN 6320-00-284-1524
NSN 5945-01-032-4742
NSN 5996-00-840-5246