Copper
Copper has the highest electrical and thermal conductivity of common engineering metals, with good corrosion resistance and formability. It is used for busbars, electrical contacts, heat exchangers, earthing and induction coils.
What it is
Electrolytic tough pitch copper (ETP, C11000) is the standard electrical grade with about 100% IACS conductivity. Oxygen-free copper (C10100/C10200) avoids hydrogen embrittlement for brazing and vacuum use. Tellurium copper and other alloys improve machinability.
Copper is soft and gummy to machine in pure form, so free-machining grades or special tooling are used for turned parts.
Typical applications
- Busbars and electrical connectors
- Earthing and lightning protection parts
- Heat exchangers and cooling blocks
- Induction coils and welding electrodes
- Switchgear components
Materials & grades
- ETP copper (C11000 / Cu-ETP)
- Oxygen-free copper (C10100 / C10200)
- Tellurium copper (C14500)
- Chromium-zirconium copper (electrodes)
Points to consider
- Pure copper machines poorly; use tellurium copper for turned parts where conductivity allows.
- Use oxygen-free copper for brazing in hydrogen or vacuum.
- Silver or tin plating improves contact performance.
- Soft copper deforms easily; handle machined parts carefully.
Frequently asked questions
Which copper grade is best for busbars?
ETP copper (C11000) is standard for busbars thanks to its high conductivity and cost.
What is oxygen-free copper?
Copper with very low oxygen content, used where parts are brazed or used in vacuum without hydrogen embrittlement.
Is copper hard to machine?
Pure copper is gummy; tellurium or other free-machining coppers machine much better.