A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5990-00-277-3763
NSN 6220-01-524-4127
NSN 5910-00-649-1970
NSN 5935-01-646-1280
NSN 5960-00-212-6367
NSN 5985-01-336-3720
NSN 5965-01-308-2261
NSN 5915-01-411-6202
NSN 6645-01-099-6887
NSN 5975-01-386-7356
NSN 6645-01-090-2555
NSN 5945-00-423-7135