A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6135-01-236-8603
NSN 5855-00-327-2112
NSN 6105-00-456-1433
NSN 6105-01-167-0446
NSN 6610-01-459-8192
NSN 5925-01-050-8195
NSN 5915-01-429-8665
NSN 2925-01-633-4048
NSN 5999-01-580-0934
NSN 6145-01-622-7811
NSN 5998-01-083-2717
NSN 5910-00-158-5389