Split Lock Washer, Hi-Collar, Steel, Plain Finish, Fits Bolt Sizes 7/16 In, Inside Dia 0.450 In, Outside Dia 0.644 In, Thickness 0.140 In, Rockwell Hardness C46, Application For Confined Areas, For Use With Socket Head Cap Screws, Meets/Exceeds ASME B 18.21. 1, Package 100