Extra Thick Washer Flat Washer Type Standard Material Steel Material Grade/Class Grade 5 Finish Black Oxide For Screw Size 1 in Inside Diameter 1.031 in Outside Diameter 2 in Maximum Thickness 0.281 in System of Measurement Inch Minimum Thickness 0.281 in Color Black Inside Diameter Tolerance +/-0.010 in Outside Diameter Tolerance +/-0.010 in Pack Size Small Pack Rockwell Hardness C4 Thickness Tolerance +0.005/-0.020 in