A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5975-01-213-0801
NSN 5985-01-106-2800
NSN 5915-00-144-5548
NSN 6220-01-379-4528
NSN 5999-01-352-5110
NSN 5998-00-451-6832
NSN 5930-01-163-9385
NSN 5960-01-450-8539
NSN 6145-00-968-6590
NSN 5855-00-149-0766
NSN 5996-01-236-8436
NSN 5985-01-604-7067