Square Washer, Dimensional Standards AMPG 2001 FL.01, Material Fiberglass, For Screw Size 1/4 in, Inside Diameter 0.266 in, Outside Diameter Not Applicable, Maximum Thickness 1/8 in, System of Measurement Inch, Minimum Thickness 7/64 in, Made in North America Made in North America, Material Quality Standards Not Applicable, Resistance Properties Chemical-Resistant, Nonconductive