Flat Washer, Dimensional Standards AMPG 2001 FL.01, Material Fiberglass, For Screw Size 1/2 in, Inside Diameter 0.516 in, Outside Diameter 7/8 in, Maximum Thickness 5/64 in, System of Measurement Inch, Minimum Thickness 3/64 in, Inside Diameter Tolerance +/-0.010 in, Made in North America Made in North America, Material Quality Standards Not Applicable, Outside Diameter Tolerance +/-0.010 in, Resistance Properties Chemical-Resistant, Nonconductive, Thickness Tolerance +0.005/-0.014 in