A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5985-01-575-1053
NSN 6645-01-141-7737
NSN 5985-00-615-9766
NSN 5965-01-063-6115
NSN 5855-00-427-7848
NSN 4140-01-500-1187
NSN 5945-01-242-9989
NSN 5950-01-222-1686
NSN 5950-00-728-2232
NSN 5855-01-449-5724
NSN 6610-01-312-5788
NSN 5925-01-560-9372