Jumbo Washer Flat Washer Type Oversized Dimensional Standards AMPG 2001 FL.05 Material Steel Material Grade/Class Grade 2 Finish Black Oxide For Screw Size 1 1/2 in Inside Diameter 1.625 in Outside Diameter 3 in Maximum Thickness 0.125 in System of Measurement Inch Minimum Thickness 0.125 in Color Black Inside Diameter Tolerance +/-0.010 in Material Quality Standards ASTM A108 Outside Diameter Tolerance +/-0.010 in Pack Size Small Pack Rockwell Hardness C40