A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5950-01-582-5575
NSN 5945-00-828-3942
NSN 6650-00-098-6128
NSN 6685-01-113-2514
NSN 6220-01-227-1917
NSN 5925-00-012-9365
NSN 5999-01-313-5283
NSN 5999-01-454-6187
NSN 5996-01-442-8296
NSN 6320-00-788-5297
NSN 6610-00-983-4482
NSN 6610-01-025-2876