A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6135-01-416-8342
NSN 5990-00-165-1809
NSN 6130-01-188-8842
NSN 5855-00-089-3974
NSN 5945-01-145-3179
NSN 5965-00-139-2809
NSN 5960-01-577-5682
NSN 5930-01-387-7956
NSN 5835-01-546-2008
NSN 5998-01-208-6450
NSN 6105-01-145-5405
NSN 5985-01-200-5041