A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5950-01-422-0467
NSN 5996-01-013-8824
NSN 6240-01-214-0308
NSN 5935-01-360-6726
NSN 5990-00-277-3763
NSN 5999-00-708-0457
NSN 5965-01-250-3214
NSN 6650-01-211-2673
NSN 6130-01-645-7766
NSN 5920-01-035-5456
NSN 6320-01-278-9832
NSN 5925-00-542-8895