A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5990-00-167-2692
NSN 5965-01-089-8579
NSN 5895-01-475-1849
NSN 5935-00-679-9663
NSN 5855-00-245-8461
NSN 5895-00-334-0047
NSN 4140-01-516-6207
NSN 7035-00-286-6221
NSN 5985-01-193-8515
NSN 2925-01-386-7392
NSN 6110-00-482-3372
NSN 5975-00-348-7427