Flat Washer Flat Washer Type Standard Dimensional Standards ASME B18.5 ASTM F-436 Material Steel Material Grade/Class Grade 2 Finish Zinc Yellow For Screw Size 3/4 in Inside Diameter 0.813 in Outside Diameter 2 in Maximum Thickness 0.149 in System of Measurement Inch Minimum Thickness 0.149 in Color Yellow Pack Size Small Pack Rockwell Hardness RC38 Thickness Tolerance +/-0.028 in Package Quantity 500