Flat Washer,1-1/2 Machined F/W 1.563 X, Dimensional Standards AMPG 2001 FL.04, Material Stainless Steel, Material Grade/Class 316, Finish Plain, For Screw Size 1 1/2 in, Inside Diameter 1.563 in, Outside Diameter 4 in, Maximum Thickness 17/64 in, System of Measurement Inch, Minimum Thickness 15/64 in, Made in North America Made in North America, Material Quality Standards ASTM A276