Split Lock Washer Lock Washer Type Split Lock Finish Blue Phosphate Material Alloy Steel For Screw Size M4 Inside Diameter 4.5 mm Outside Diameter 7.3 mm Maximum Thickness 1 mm Minimum Thickness 1 mm Color Blue Dimensional Standards DIN 127 Material Grade/Class Not Graded Pack Size Small Pack Rockwell Hardness HRC44 System of Measurement Metric Thickness Tolerance +/-0.1 mm Package Quantity 100