A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6105-01-395-6658
NSN 6320-01-322-8340
NSN 6685-01-493-4883
NSN 5920-01-528-2509
NSN 5925-01-262-6152
NSN 6620-01-076-8706
NSN 5920-00-994-0558
NSN 5920-01-230-7847
NSN 2925-01-172-4785
NSN 5930-01-550-2828
NSN 6320-01-039-5891
NSN 5910-01-275-7259