Split Lock Washer, Finish Black Oxide, Material Steel, For Screw Size 3/8 in, Inside Diameter 0.377 in, Outside Diameter 0.67 in, Maximum Thickness 0.07 in, Minimum Thickness 0.07 in, Color Black, Dimensional Standards ASME B18.21.1, Material Grade/Class Not Graded, Pack Size Bulk Pack, Rockwell Hardness C38, System of Measurement Inch, Thickness Tolerance -, Package Quantity 10000