A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6650-00-059-6268
NSN 5950-01-272-2679
NSN 5945-01-208-4943
NSN 5895-00-701-9458
NSN 6110-01-416-6306
NSN 5960-01-144-9183
NSN 6150-00-599-0721
NSN 7035-01-607-5481
NSN 2925-00-753-8598
NSN 5950-00-104-8113
NSN 5945-01-459-5840
NSN 5855-01-452-1406