A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5920-00-254-8429
NSN 5930-01-367-2184
NSN 5965-01-267-3812
NSN 6150-01-436-7107
NSN 5835-01-471-5848
NSN 6320-01-150-5378
NSN 4140-00-223-7492
NSN 2925-00-447-9976
NSN 4140-01-303-7157
NSN 6645-00-503-1379
NSN 5925-00-914-6516
NSN 5996-01-367-0778