A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6110-00-582-7504
NSN 5945-01-421-7795
NSN 6320-01-287-5345
NSN 6650-01-538-6898
NSN 5925-00-090-7403
NSN 6320-01-512-2031
NSN 5985-01-406-2439
NSN 2925-01-282-3206
NSN 5910-01-445-9128
NSN 5965-01-555-8775
NSN 6240-00-235-5159
NSN 6240-00-765-4220