Flat Washer Flat Washer Type Standard Dimensional Standards DIN 125-1A Material Steel Material Grade/Class Grade 5 Finish Zinc Yellow For Screw Size M18 Inside Diameter 19 mm Outside Diameter 34 mm Maximum Thickness 3 mm System of Measurement Metric Minimum Thickness 3 mm Pack Size Small Pack Thickness Tolerance +/-0.30mm Package Quantity 25