Vacuum Components

ConFlat (CF) flanges use a copper gasket that is cold-welded between two stainless steel knife edges, creating a true metal-to-metal hermetic seal capable of achieving system pressures below 10⁻¹² torr and helium leak rates of 10⁻¹³ torr·L/s or better. KF (Klein Flange, also called NW or ISO-KF) flanges use an

Direct Answer Choose CF flanges when your system must reach pressures at or below 10⁻⁷ torr, requires bakeout above 150°C, or must meet a helium leak-rate specification at or below 1×10⁻⁹ atm·cc/sec. Choose KF flanges for rough vacuum, high vacuum up to about 10⁻⁷ torr, and any connection that benefits