Copper properties and applications
Copper is a highly conductive metal used in electrical, thermal, and RF applications. It offers excellent conductivity and corrosion resistance.
- Electrical conductivity — excellent (second only to silver)
- Thermal conductivity — excellent
- Corrosion resistance — good
- Machinability — fair (ductile, gummy)
- Common grades — C110 (electrolytic), C101 (oxygen-free)
Oxygen-free copper (C101) is preferred for applications requiring high conductivity, such as RF components.
Copper machining challenges
- Ductility — copper is soft and tends to form built-up edges
- Tool wear — copper is abrasive, causing tool wear
- Burr formation — copper tends to form burrs
- Heat generation — copper conducts heat away, but cutting still generates heat
- Chip control — copper produces long, stringy chips
Choose a supplier with experience in copper machining. Copper requires specific tooling and techniques that not all shops have.
Best practices for copper machining
- Use sharp tools — sharp tools reduce built-up edge formation
- Maintain consistent feeds — avoid dwell and vibration
- Use coolant — reduces heat and improves surface finish
- High speeds, moderate feeds — reduces tool wear and improves finish
- Consider chip breakers — helps control stringy chips
Using dull tools for copper machining. Dull tools increase built-up edge formation and reduce tool life.
Typical copper components
- Electrical busbars — high-current applications
- RF components — waveguides, antennas
- Heat exchangers — thermal management
- Electrical connectors — terminals, plugs
- EDM electrodes — for electrical discharge machining
Frequently Asked Questions
Is copper difficult to machine?
Copper is challenging to machine due to its ductility and tendency to form built-up edges. However, with the right tooling and techniques, it can be machined effectively.
What is the best grade of copper for machining?
Tellurium copper (C145) is free-machining, but C110 and C101 are also commonly machined for electrical applications.
What tolerance can copper machining achieve?
Typical tolerance is ±0.01mm, with precision capability of ±0.005mm.
What applications use copper?
Electrical components, RF applications, heat exchangers, and EDM electrodes.