Lock Washer Lock Washer Type Internal Tooth Lock Finish Zinc Plated Material Steel For Screw Size #10 Inside Diameter 10.5 mm Outside Diameter 17.57 mm Maximum Thickness 0.89 mm Dimensional Standards ASME B18.21.1 For Use With Machine Screws and Nuts Material Grade/Class Not Graded Pack Size Small Pack Rockwell Hardness C40 to C50 System of Measurement Inch Thickness Tolerance -0.006 in Package Quantity 100