A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6135-01-329-7994
NSN 5905-01-354-0879
NSN 5975-00-553-7151
NSN 5910-00-740-2926
NSN 5925-01-397-4991
NSN 2925-00-973-9413
NSN 6150-01-547-3061
NSN 5910-01-513-2713
NSN 5895-00-984-1945
NSN 5915-01-201-2937
NSN 6135-01-032-8887
NSN 5930-00-960-6424