Square Washer Type Square Material Steel Material Grade/Class Grade 2 Finish Galvanized For Screw Size 5/8 in Inside Diameter 0.688 in Square Width 2 in Maximum Thickness 0.265 in System of Measurement Inch Minimum Thickness 0.235 in Pack Size Small Pack Resistance Properties Corrosion Resistant Rockwell Hardness B55 Thickness Tolerance +/-0.030 in