Split Lock Washer, Finish Black Oxide, Material Steel, For Screw Size 3 in, Inside Diameter 3.012 in, Outside Diameter 4.16 in, Maximum Thickness 0.526 in, Minimum Thickness 0.526 in, Dimensional Standards ASME B18.21.1, Material Grade/Class Not Graded, Pack Size Small Pack, Rockwell Hardness C40 to C50, Package Quantity 5