A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6130-01-363-0488
NSN 6130-00-064-1517
NSN 5965-01-105-7901
NSN 6105-01-337-4403
NSN 5895-00-150-7072
NSN 5990-01-572-3137
NSN 5975-01-337-5658
NSN 6685-01-317-9892
NSN 5985-00-084-3753
NSN 5835-01-295-9220
NSN 6610-01-301-3513
NSN 5835-00-170-5238