Split Lock Washer, Heavy Duty, Steel, Finish Zinc, Fits Bolt Sizes 9/16 In, Inside Dia. 0.564 In, Outside Dia. 0.975 In, Thickness 0.170 In, Thickness Tolerance + 0.010 In, Color Silver, Rockwell Hardness C38-46, N/A, Meets/Exceeds ASME B 18.21. 1, Package Quantity 50. This item has been restricted from sale in the following state (s): []