Stainless Steel Vacuum Blank 2.5" OD for 2" Conflat CF Flange Seal Cap Cover

Stainless Steel Vacuum Blank 2.5" OD for 2" Conflat CF Flange Seal Cap Cover

This is a stainless steel vacuum blank disc sized for 2" Conflat (CF) flange fittings, with an outer diameter of 2.5". Vacuum blanks are solid metal discs used to seal off unused or temporarily inactive ports on vacuum chambers, preventing air ingress and maintaining system vacuum integrity. This blank has no through-holes and mates to the CF flange knife-edge with a copper or aluminum gasket (not included) to form a high-integrity seal.

Specifications & What's Included

• Material: Stainless steel
• Outer Diameter (OD): 2.5"
• Compatible Flange Standard: 2" Conflat (CF)
• Configuration: Solid blank (no through-holes or ports)
• Stepped rim/raised seating surface visible on flange face for knife-edge gasket engagement
• Unbranded / no manufacturer markings
• Blank disc only — fasteners and gasket not included

Applications

Conflat (CF) flanges are the standard connection system for high-vacuum (HV) and ultra-high-vacuum (UHV) equipment, capable of sustaining pressures down to the 10⁻¹⁰ Torr range. Vacuum blanks like this one are standard hardware in any vacuum system — used to cap unused ports on vacuum chambers, deposition systems, sputter coaters, ion beam systems, surface analysis instruments (XPS, AES, LEED), mass spectrometers, electron microscopes, and research apparatus. They are also commonly used during system bakeout or reconfiguration when a port needs to be temporarily closed. The CF blank flanges directly onto a 2" CF port using the standard bolt circle and a soft metal (copper or aluminum) gasket compressed against the knife-edge to form a leak-tight metal seal. This style of blank has been in widespread use since CF flanges were standardized in the 1960s and remains current hardware in laboratory and semiconductor vacuum systems today.