A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6610-01-451-3877
NSN 5985-01-232-4250
NSN 6320-01-445-8192
NSN 5855-01-178-6396
NSN 6645-01-032-5337
NSN 6620-01-385-6172
NSN 6130-01-218-5682
NSN 7035-00-517-8232
NSN 6135-01-463-2445
NSN 5920-00-068-7353
NSN 5990-01-097-4721
NSN 5835-00-170-5238