A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6105-01-423-6617
NSN 6650-01-216-2707
NSN 5910-01-192-1848
NSN 6150-01-215-1529
NSN 4140-01-123-9149
NSN 6110-01-443-5010
NSN 5985-01-532-5025
NSN 5835-01-436-6549
NSN 6620-00-121-9702
NSN 5950-00-949-5987
NSN 6610-01-081-9237
NSN 6110-01-627-1354