Flat Washer Flat Washer Type Standard Material Stainless Steel Material Grade/Class 18-8 Finish Plain For Screw Size M24 Inside Diameter 25 mm Outside Diameter 40 mm Maximum Thickness 4 mm System of Measurement Metric Minimum Thickness 4 mm Inside Diameter Tolerance +/-0.010 in Material Quality Standards ASTM A582 Outside Diameter Tolerance +/-0.010 in Pack Size Small Pack Resistance Properties Chemical Resistant Corrosion Resistant Rockwell Hardness B83