Sealing Washer Finish Plain Metal Material Copper Material Grade/Class Not Graded For Screw Size M12 Inside Diameter 12 mm Outside Diameter 16 mm Maximum Thickness 1.5 mm Seal Material Copper System of Measurement Metric Pack Size Small Pack Heat Treatment Annealed Minimum Thickness 1.5 mm Thickness Tolerance +/-0.20 mm Package Quantity 50