A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6685-01-376-4735
NSN 5975-01-514-4465
NSN 5985-01-552-5261
NSN 5960-01-325-2241
NSN 6645-01-317-6071
NSN 6150-00-157-3126
NSN 6610-01-472-2757
NSN 6135-00-422-3967
NSN 5950-01-572-0569
NSN 5965-00-864-8046
NSN 6240-00-299-8474
NSN 6105-01-585-2502