A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5965-00-153-5216
NSN 5915-00-294-9419
NSN 6645-01-109-5200
NSN 6150-01-379-3966
NSN 5855-00-327-2061
NSN 5920-00-417-8768
NSN 6645-01-100-3296
NSN 5930-01-199-1645
NSN 6105-00-317-5688
NSN 5905-00-720-0750
NSN 5985-01-359-9182
NSN 5925-00-761-0105