A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5930-00-284-3518
NSN 5935-01-247-7173
NSN 5960-00-302-5754
NSN 6620-00-278-7313
NSN 5910-00-501-5265
NSN 6645-01-336-5019
NSN 6105-00-787-9115
NSN 5905-01-349-7705
NSN 5965-00-224-8798
NSN 5895-01-531-7013
NSN 6650-00-985-5332
NSN 5965-01-147-5847