Split Lock Washer, Light Duty, Steel, Finish Plain, Fits Bolt Sizes 1/2 In, Inside Dia. 0.502 In, Outside Dia. 0.867 In, Thickness 0.099 In, Thickness Tolerance + 0.010 In, Color Black, Rockwell Hardness C38-46, N/A, Meets/Exceeds ASME B 18.21. 1, Package Quantity 50