A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 7035-01-374-7220
NSN 6320-00-682-3448
NSN 5996-01-046-3594
NSN 5996-00-135-7367
NSN 5960-00-614-3998
NSN 6130-00-518-4305
NSN 6645-01-613-7389
NSN 5835-00-725-2087
NSN 5920-01-044-5621
NSN 5998-01-176-9256
NSN 4140-01-504-8326
NSN 5990-00-424-8872