Flat Washer Flat Washer Type Oversized Dimensional Standards DIN 9021 Material Steel Material Grade/Class Grade 2 Finish Zinc Plated For Screw Size M12 Inside Diameter 13 mm Outside Diameter 37 mm Maximum Thickness 3 mm System of Measurement Metric Minimum Thickness 3 mm Color Silver Inside Diameter Tolerance 0.512-0.522 Made in North America No Manufacturer Location Globally Sourced Material Quality Standards Not Rated Maximum Temperature 350 Degrees C