OFHC Copper CF Tube Assembly – for UHV Applications, Connection, Filling & Pinch-Off

Our CF copper tube assemblies are manufactured from ultra-pure OFHC (Oxygen-Free High Conductivity) copper and are designed for use in high and ultra-high vacuum (UHV) environments. Available in multiple CF sizes, they provide a versatile solution for system connection, filling, evacuation, and — if required — permanent sealing via pinch-off.

Key Features

• Material: OFHC Copper (≥ 99.99% purity)
• Tube Length: 160 mm (6 inches)
• Tube Diameters:
  • 3/8" (9.525 mm OD) – suitable for manual pinch-off (e.g. hand tools)
  • 1/2" (12.7 mm OD) – suitable for pneumatic pinch-off tools and robust connections
• Configurations:
  • Open tube end
  • CF flange
  • VCR male gland (e.g. VCR8 1/2") including pre-installed male nut
• Flanges: Rotatable CF flanges for easy alignment
• Surface Finish: Vacuum-compatible, smooth and burr-free
• Cleaning: Cleaned for high vacuum (HV), UHV-ready
• Origin: 🇨🇭 Swiss Made – precision manufactured

Manufacturing Process

All assemblies are vacuum brazed at 1050°C ±15°C under high vacuum conditions using BNi-2 (nickel-based brazing alloy), ensuring excellent joint integrity and vacuum compatibility.

VCR Connection

The assembly is equipped with a VCR male gland including the required male nut pre-installed prior to welding.

The corresponding female nut and metal gasket are not included and must be supplied separately.

Benefits

• Excellent thermal and electrical conductivity
• Low outgassing – suitable for UHV applications after bake-out
• Reliable, leak-tight metal sealing
• Requires only a 1/4 turn for sealing when using VCR connections
• Compatible with standard CF vacuum hardware
• Suitable for both permanent sealing and flexible system integration

Typical Applications

• Vacuum system connection
• Filling and evacuation lines
• Temporary or semi-permanent UHV setups
• Cryogenic and research applications
• Pinch-off processes (optional use)

Important Note

These assemblies are supplied in standard configurations. Custom lengths and designs are available upon request at additional cost.

Acknowledgement

Special thanks to Peng Yuan Han (@dso.org.sg) for valuable technical input and collaboration.