187 in, Inside Diameter Tolerance +/-0.187 in, System of Measurement Inch, Minimum Thickness 0.010 in, Material Quality Standards ASTM A582, Outside Diameter Tolerance +/-0.Extra Thick Washer, Flat Washer Type Standard, Material Stainless Steel, Material Grade/Class 18-8, Finish Plain, For Screw Size 1/4 in, Inside Diameter 0.