Split Lock Washer Lock Washer Type Split Lock Finish Zinc Plated Material Steel For Screw Size M20 Inside Diameter 20.2 mm Outside Diameter 30.6 mm Maximum Thickness 4.5 mm Minimum Thickness 4.5 mm Dimensional Standards DIN 7980 Material Grade/Class Not Graded Pack Size Small Pack Rockwell Hardness C38 Package Quantity 10