SAE Washer, Flat Washer Type SAE, Dimensional Standards ASME B18.22.1, Material Steel, Material Grade/Class Grade 2, Finish Black Oxide, For Screw Size #12, Inside Diameter 0.25 in, Outside Diameter 9/16 in, Maximum Thickness 0.063 in, System of Measurement Inch, Minimum Thickness 0.063 in, Pack Size Small Pack, Rockwell Hardness RB40, Thickness Tolerance +/-0.015 in, Package Quantity 100