A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6620-00-663-8962
NSN 5910-01-461-7800
NSN 5935-01-035-2947
NSN 6610-01-485-5083
NSN 6110-01-091-3797
NSN 6145-01-134-0835
NSN 5920-00-079-9377
NSN 5950-01-449-9118
NSN 5960-00-413-8129
NSN 5930-01-167-7741
NSN 5975-01-241-0540
NSN 6105-00-152-3825