A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5905-01-189-3101
NSN 7035-01-215-2449
NSN 5985-01-449-0939
NSN 5935-01-295-9723
NSN 6320-01-466-4175
NSN 5990-01-564-9532
NSN 6110-01-517-3811
NSN 5930-00-913-9814
NSN 2925-01-014-0118
NSN 5835-01-576-9013
NSN 6610-01-611-5323
NSN 6685-01-408-6372