A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6610-00-935-7131
NSN 5990-01-085-3765
NSN 5945-01-086-4415
NSN 6220-01-562-3819
NSN 5975-01-357-9479
NSN 5910-01-448-2324
NSN 5985-01-273-7323
NSN 5945-01-391-2699
NSN 5999-01-214-8420
NSN 6620-01-289-8486
NSN 5930-00-605-2853
NSN 6650-01-199-4967