A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5915-00-170-6775
NSN 5975-00-726-8370
NSN 6620-01-502-9104
NSN 5930-00-291-0852
NSN 5895-01-468-9916
NSN 5990-01-199-2846
NSN 5895-01-420-5887
NSN 5965-01-375-5238
NSN 5930-00-632-1369
NSN 6105-00-911-2783
NSN 5910-00-161-6869
NSN 6105-00-275-0826