A copper gasket is the standard metal seal for CF flanges, widely trusted in ultra-high vacuum systems where elastomer O-rings cannot survive high baking temperatures or meet strict low-outgassing requirements. Made from oxygen-free high-conductivity copper, this soft metal gasket forms a permanent hermetic seal when the knife-edge of a CF flange cuts slightly into its surface under bolt torque.

Unlike rubber seals, a copper gasket can tolerate repeated baking up to 450°C, a must for removing adsorbed water and gas molecules inside UHV chambers. It delivers an extremely low helium leak rate, essential for surface analysis instruments, particle accelerators, semiconductor process chambers and high vacuum test stations. Once compressed, the copper gasket deforms plastically; for critical vacuum applications, technicians often replace it after every disassembly to avoid virtual leaks and seal failure.

Quality matters greatly. Impure copper, scratches, oxidation or surface contamination will ruin sealing performance. Before installation, each copper gasket should be inspected visually and kept clean, without fingerprints, grease or dust. We supply standard copper gaskets for common CF sizes, along with vacuum bellows, CF flanges and other supporting vacuum components. If you need copper gaskets with reliable material certification or custom vacuum sealing parts, reach out to our team for datasheets and quotations.