A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5996-01-597-0977
NSN 6135-00-112-8637
NSN 5930-01-542-9182
NSN 4140-01-218-9013
NSN 6135-01-355-8917
NSN 5975-01-199-5471
NSN 5910-01-322-0918
NSN 5920-01-066-3117
NSN 5975-00-414-7143
NSN 5960-01-462-1864
NSN 6220-01-391-5323
NSN 5975-00-826-8982