Structural Flat Washer Flat Washer Type Standard Material Steel Material Grade/Class Not Graded Finish Hot Dipped Galvanized For Screw Size 5/8 in Inside Diameter 0.172 in Outside Diameter 1 5/16 in Maximum Thickness 0.177 in System of Measurement Inch Minimum Thickness 0.122 in Material Quality Standards ASTM F436 Pack Size Small Pack Rockwell Hardness C26 Thickness Tolerance 0.122 to 0.177 in Package Quantity 50