Flat Washer,4 In. Machined F/W 4.125 X 7.5, Dimensional Standards AMPG 2001 FL.04, Material Stainless Steel, Material Grade/Class 316, Finish Plain, For Screw Size 4 in, Inside Diameter 4.125 in, Outside Diameter 7 1/2 in, Maximum Thickness 17/64 in, System of Measurement Inch, Minimum Thickness 15/64 in, Inside Diameter Tolerance +/-0.010 in, Made in North America Made in North America, Material Quality Standards ASTM A276, Outside Diameter Tolerance +/-0.010 in