Slotted Washer Finish Plain Flat Washer Type Slotted Flat Washer For Screw Size 1/2 in Material Stainless Steel Material Grade/Class 18-8 Maximum Thickness 0.375 in Minimum Thickness 0.375 in Outside Diameter 2 1/4 in Pack Size Small Pack Rockwell Hardness B83 to B95 Slot Width 0.531 in System of Measurement Inch Thickness Tolerance +/-0.010 in