L.H. Dottie HN632 Hex Nut for Machine Screw No.6-32 TPI, Zinc Plated, 100-Pack Zinc plated-general use Invincibox up to 1/2-inch Hex machine screw nuts are for screws smaller than 1/4-inch diameter #6-32 TPI, is made of steel 0.21 lb. weight