Split Lock Washer Lock Washer Type Split Lock Finish Black Oxide Material Steel For Screw Size 3 in Inside Diameter 3.012 in Outside Diameter 4.074 in Maximum Thickness 0.458 in Minimum Thickness 0.458 in Dimensional Standards ASME B18.21.1 Material Grade/Class Not Graded Pack Size Small Pack Rockwell Hardness C38 Package Quantity 5