Slotted Washer, Color Black, Finish Black Oxide, Flat Washer Type Slotted Flat Washer, For Screw Size 1/2 in, Material Steel, Material Grade/Class Grade 5, Maximum Thickness 0.375 in, Minimum Thickness 0.375 in, Outside Diameter 1 7/8 in, Pack Size Small Pack, Rockwell Hardness C40 Surface, Slot Width 0.531 in, System of Measurement Inch, Thickness Tolerance +/-0.015 in