A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5920-01-315-4366
NSN 5905-00-518-7540
NSN 5920-00-808-0037
NSN 6320-01-029-4220
NSN 5855-01-417-3250
NSN 5950-01-303-4733
NSN 4140-01-618-0996
NSN 5975-00-055-7277
NSN 6145-01-024-9848
NSN 5999-01-366-2024
NSN 6620-01-398-8986
NSN 4140-01-202-8670