Flat Washer, Flat Washer Type Standard, Dimensional Standards DIN 125-1A, Material Steel, Material Grade/Class 200HV, Finish Zinc-Plated, For Screw Size M20, Inside Diameter 21.33 mm, Outside Diameter 37 mm, Maximum Thickness 3.3 mm, System of Measurement Metric, Minimum Thickness 2.7 mm, Color Silver, Inside Diameter Tolerance 0.827-0.84, Made in North America Not Made in North America, Manufacturer Location Globally Sourced, Material Quality Standards ASTM A-325