Lock Washer, Carbon Steel, Carbon Steel, Finish Zinc Plated, Fits Bolt Sizes 6mm, M6, Inside Dia. 6.3 mm, Outside Dia. 10.8 mm, Thickness 1.77 mm, Thickness Tolerance +/- 0.28 mm, Color Gray, Rockwell Hardness C46, Helps Prevent Loosening, For Use With Bolts, Package Quantity 200