A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5996-01-627-3817
NSN 5905-01-229-0246
NSN 5935-01-370-7152
NSN 5895-01-244-9819
NSN 5855-01-486-9924
NSN 6145-01-626-1836
NSN 6610-01-389-3082
NSN 6240-00-594-7138
NSN 5985-00-649-8781
NSN 5960-01-209-2410
NSN 6220-01-457-5013
NSN 6150-00-964-7303