A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5835-00-257-2852
NSN 6240-00-334-6766
NSN 5855-01-006-1827
NSN 5965-00-661-0469
NSN 5999-00-349-6194
NSN 6145-00-726-3720
NSN 5915-01-253-5000
NSN 5905-01-307-4566
NSN 2925-00-526-4541
NSN 6150-00-965-5740
NSN 5895-00-933-9923
NSN 6220-01-200-7910