Shim,SHIM F/W 1/2(.500-.511)X3/4(.748-., Dimensional Standards AMPG 2001 FL.04, Material Steel, Material Grade/Class Case Hardened, Finish Plain, For Screw Size 1/2 in, Inside Diameter 0.511 in, Outside Diameter 3/4 in, Maximum Thickness 3/16 in, System of Measurement Inch, Minimum Thickness 3/16 in, Made in North America Made in North America, Material Quality Standards ASTM A108