A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6620-01-452-1161
NSN 5895-00-830-8975
NSN 6220-01-051-2080
NSN 6240-01-649-2988
NSN 5925-01-514-7048
NSN 6685-01-449-4984
NSN 5935-00-369-8000
NSN 2925-01-533-7904
NSN 5990-00-498-5934
NSN 6620-01-540-5712
NSN 7035-00-193-2269
NSN 5895-00-603-0471