Lock Washer, Steel, Delta Protect Finish, Fits Bolt Sizes 5/16", Inside Dia. 0.340", Outside Dia. 0.650", Thickness 0.100", Thickness Tolerance +/- 0.01", Rockwell Hardness Min. 46 HRC, Meets/Exceeds DIN 25201, Package Quantity 200. This item has been restricted from sale in the following state (s): []