A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6610-01-163-7062
NSN 5925-00-233-7523
NSN 6320-00-925-0558
NSN 5910-01-361-0380
NSN 6110-01-197-9850
NSN 5925-01-300-9745
NSN 4140-00-899-3086
NSN 5985-00-170-8536
NSN 5925-00-729-9854
NSN 6105-01-527-5270
NSN 5920-01-386-3188
NSN 6130-00-270-6930