A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5930-01-064-6417
NSN 5998-01-250-5824
NSN 5930-01-101-9589
NSN 5895-01-168-2509
NSN 5965-01-386-2988
NSN 5945-01-502-9531
NSN 6240-01-207-3863
NSN 5965-00-673-9843
NSN 5835-01-531-0379
NSN 6645-01-400-1137
NSN 6105-01-101-0233
NSN 6150-00-526-3720