MDC’s 2-3/4" O.D. Conflat® (CF) flange, classified as DN40CF, features an outer diameter of 2.75" (69.85 mm) and is machined from high-quality 304 stainless steel. Designed for ultrahigh vacuum (UHV) systems requiring high temperature resistance and precise sealing, this flange is ideal for scientific, semiconductor, and industrial vacuum applications. Its compatibility with standard CF components and availability in both rotatable and nonrotatable geometries ensures flexibility in integration.

Key Features

DN40CF Designation – 2-3/4" O.D. (69.85 mm)
Material: 304 stainless steel for corrosion resistance and UHV integrity
Vacuum Rating: UHV performance down to 1×10⁻¹³ Torr (1.33×10⁻¹¹ Pa)
Temperature Rating: Bake-out compatible up to 450°C (842°F)
Geometry Options: Offered in rotatable and nonrotatable versions
Gasket Compatibility: Supports OFE copper or optional Viton® (FKM) elastomer seals
Bolt Hole Options: Through-hole flanges: 6 bolt holes drilled Ø 0.265" (6.73 mm). Tapped flanges: 6 bolt holes threaded 0.250-28 UNF
Conflat® Compatible: Industry-standard sealing interface for vacuum systems

Applications

The 2-3/4" Conflat® flange (DN40CF) in 304 stainless steel is widely used in UHV systems for mass spectrometry, thin film deposition, surface analysis, electron microscopy, and semiconductor processing. Its high thermal tolerance and precision-sealing performance make it a key component in beamline experiments, research laboratories, and vacuum chamber assemblies demanding reliable, repeatable vacuum performance.