Flat Washer, Dimensional Standards AMPG 2001 FL.01, Material Stainless Steel, Material Grade/Class Through Hardened, Finish Plain, For Screw Size #6, Inside Diameter 0.156 in, Outside Diameter 4 in, Maximum Thickness 3/32 in, System of Measurement Inch, Minimum Thickness 1/16 in, Inside Diameter Tolerance +/-0.010 in, Made in North America Made in North America, Material Quality Standards ASTM A564 Type 630, Outside Diameter Tolerance +/-0.010 in