Plain Washer Flat Washer Type Standard Dimensional Standards DIN 7349 Material Steel Material Grade/Class Grade 2 Finish Zinc Plated For Screw Size M8 Inside Diameter 8.4 mm Outside Diameter 21 mm Maximum Thickness 4 mm System of Measurement Metric Minimum Thickness 4 mm Maximum Temperature 302 Degrees F Minimum Temperature -58 Degrees F Pack Size Small Pack Package Quantity 100