A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5920-00-761-0134
NSN 5925-01-288-8651
NSN 5915-01-610-5168
NSN 5945-01-025-0504
NSN 6610-01-131-2636
NSN 5895-01-376-7655
NSN 6320-01-549-7201
NSN 5930-01-616-7597
NSN 5975-00-521-2140
NSN 5935-00-880-5050
NSN 6105-01-123-8887
NSN 5996-01-013-8824