Flat Washer, Flat Washer Type Standard, Dimensional Standards ASME B18.22.1, Material Steel, Material Grade/Class Grade 2, Finish Zinc Plated, For Screw Size 1/2 in, Inside Diameter 0.531 in, Outside Diameter 1 in, Maximum Thickness 0.071 in, System of Measurement Inch, Minimum Thickness 0.056 in, Color Silver, Inside Diameter Tolerance +/-0.010 in, Outside Diameter Tolerance +/-0.010 in, Pack Size Small Pack, Rockwell Hardness B55, Thickness Tolerance -0.014 in/ +0.005 in, Package Quantity 10