A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6320-01-346-5158
NSN 6105-00-283-9153
NSN 5950-01-265-0880
NSN 6650-01-536-3977
NSN 5920-01-188-6458
NSN 7035-01-216-4806
NSN 5905-00-707-1030
NSN 6220-01-605-1346
NSN 5990-01-074-6549
NSN 5855-01-010-4921
NSN 5920-01-629-0223
NSN 5905-00-722-1167