Oxygen Free High Conductivity Copper (OFHC)

Tig Welding in Moist Atmosphere


Hydrogen Embrittlement Test




Oxygen free high conductivity copper is produced by the direct conversion of selected refined cathodes under carefully controlled conditions to prevent any contamination of the pure oxygen-free metal during processing. The method of producing OFHC copper insures extra high grade of metal with a copper content of 99.996%. With so small a content of extraneous elements, the inherent properties of elemental copper are brought forth to a high degree. Characteristics are high ductility, high electrical and thermal conductivity, high impact strength, good creep resistance, ease of welding, and low volatility under high vacuum.

Oxygen free high conductivity copper contains less than 10 ppm oxygen in the metal and is completely free from copper oxide particles.

Lower oxygen content in oxygen free high conductivity copper has many advantages over ETP copper as shown in the following table.

OFHC Copper ETP Copper
Contains less than 10 ppm of oxygen. (.001% oxygen) Contains 150 - 400 ppm oxygen. (.015-.04% oxygen)
Superior electrical and thermal conductivity. Minimum 100% IACS Conductivity. Electrical and thermal conductivity may vary on processing semis.Minimum 99.99% IACS Conductivity
Passes close bend test (hydrogen embrittlement test.) Cannot pass close bend test.
Better thermal cycle behavior. Poor thermal cycle behavior.
Consistency in brazed & welded joints can be achieved. May lead to inconsistent brazed & welded joints.
Most suitable for use in high vacuum devices. Not Suitable.


  • Electrical - energy, power and transportation systems, electrical stampings and pressings, magnet windings, commutators and many other applications.
  • Electronics - vacuum tubes for radio and tv transmitters, vacuum capacitors, vacuum interrupters, magnetrons, heat sinks, bases for semiconductors and substrates as well as targets and backing plates in sputtering devices.
  • telecom
  • Heat transfer - energy and heat transfer systems, solar thermal panels.
  • Superconductors