A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5960-00-786-3219
NSN 7035-01-395-0757
NSN 4140-00-849-9295
NSN 6685-01-288-8408
NSN 6620-00-193-9503
NSN 5975-01-136-4988
NSN 5905-01-444-3706
NSN 5855-01-100-3272
NSN 6320-00-070-4544
NSN 6220-00-449-6016
NSN 5999-01-511-1962
NSN 5965-00-011-6742