Flat Washer Flat Washer Type Standard Dimensional Standards DIN 125-1A Material Steel Material Grade/Class Grade 5 Finish Zinc Plated For Screw Size M3.5 Inside Diameter 3.7 mm Outside Diameter 8 mm Maximum Thickness 0.5 mm System of Measurement Metric Minimum Thickness 0.5 mm Pack Size Small Pack Rockwell Hardness Not Rated Package Quantity 100