Plain Washer Flat Washer Type Standard Dimensional Standards DIN 433 Material Steel Material Grade/Class Grade 2 Finish Zinc Plated For Screw Size M12 Inside Diameter 13 mm Outside Diameter 20 mm Maximum Thickness 2 mm System of Measurement Metric Minimum Thickness 2 mm Maximum Temperature 302 Degrees F Minimum Temperature -58 Degrees F Pack Size Small Pack Package Quantity 100