A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5965-01-209-2838
NSN 5855-01-450-8820
NSN 5950-01-445-5586
NSN 6645-01-028-2186
NSN 6610-00-226-4710
NSN 5930-01-158-1508
NSN 6650-01-410-7526
NSN 5925-01-145-5330
NSN 5895-01-047-7379
NSN 5975-01-620-0076
NSN 5960-01-437-5318
NSN 5915-01-633-9845