A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6105-01-525-9840
NSN 5998-01-582-0576
NSN 5990-01-429-6211
NSN 5905-01-147-6108
NSN 6145-01-340-8071
NSN 6130-00-314-4742
NSN 6105-01-410-8948
NSN 5999-00-487-3273
NSN 4140-00-357-1188
NSN 6645-00-357-8827
NSN 2925-00-808-5077
NSN 5950-00-529-0599