A Copper Gasket is used to mate two Conflat (CF) vacuum flanges together. The CF flange is the most widely used flange type for high vacuum and UHV applications. These flanges must be the same outer dimension. Almost all of our feedthroughs and fittings are available on this flange system. All of our Copper Gaskets are OFHC (Oxygen-Free High Conductivity) copper alloy 101 (99.99% Pure copper). The gaskets are punched from a copper plate, chemically cleaned, and then packaged to minimize scratches and burs. These Copper Gaskets are designed to be used in the industry standard "captured copper gasket" sealing principle. See the drawing to the left to get a visual representation of how the copper gasket is used by utilizing the knife edge of the flange. This is how it creates the seal between two mating flanges. This is a standard sealing method throughout the scientific vacuum industry.