A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5930-00-595-5489
NSN 5998-00-618-0235
NSN 2925-01-164-9579
NSN 7035-01-271-1643
NSN 5945-00-814-4680
NSN 5965-01-573-2653
NSN 6145-01-392-0910
NSN 6145-01-337-5554
NSN 6685-01-322-8386
NSN 5990-00-226-1152
NSN 6645-01-113-8979
NSN 5905-01-247-3754