A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6650-00-543-6023
NSN 5975-01-161-7316
NSN 6620-01-335-2443
NSN 6610-01-256-5485
NSN 6130-01-044-6382
NSN 6620-01-322-5576
NSN 6650-00-938-2153
NSN 5935-01-376-4949
NSN 5925-01-030-4673
NSN 5950-00-336-3316
NSN 5985-01-406-3038
NSN 5985-01-485-4750