Extra Thick Washer Flat Washer Type Standard Material Steel Material Grade/Class Grade 5 Finish Black Oxide For Screw Size M10 Inside Diameter 10.5 mm Outside Diameter 23 mm Maximum Thickness 5 mm System of Measurement Metric Minimum Thickness 5 mm Color Black Inside Diameter Tolerance +/-0.010 in Outside Diameter Tolerance +/-0.010 in Pack Size Small Pack Rockwell Hardness C4 Thickness Tolerance +0.40mm/-0.50mm Package Quantity 5