Flat Washer, Dimensional Standards AMPG 2001 FL.01, Material Stainless Steel, Material Grade/Class 18-8, Finish Plain, For Screw Size 5/16 in, Inside Diameter 0.344 in, Outside Diameter 11/16 in, Maximum Thickness 1/8 in, System of Measurement Inch, Minimum Thickness 1/8 in, Made in North America Made in North America, Material Quality Standards ASTM A582, Resistance Properties Chemical-Resistant, Corrosion-Resistant, Dye-Resistant, Food-Resistant, Nitric Acid-Resistant