Sealing Washer Sealing Washer Type Metal Bonded Washer Finish Cadmium Plated Metal Material Steel Material Grade/Class Not Graded For Screw Size M18 Inside Diameter 18.796 mm Outside Diameter 26 mm Maximum Thickness 2.4 mm Seal Material Buna-N System of Measurement Metric Pack Size Small Pack Maximum Temperature 220 Degrees F Minimum Temperature -40 Degrees F Minimum Thickness 1.5 mm Seal Material Color Silver/Gold Thickness Tolerance +/-0.20 mm