Copper CNC Machining For Beginners
2025/10/7
Copper is a soft and easily workable metal that falls into the low-hardness category, making it ideal for complex shapes and precision CNC machining. It is also a colored metal with exceptional thermal and electrical conductivity. Copper has the second-lowest electrical resistance among metals at room temperature, after silver, and is used in applications including electrical wiring and batteries. Copper exhibits four primary characteristics:
High Electrical Conductivity
High Thermal Conductivity
Non-magnetic
Usability in Extremely Low-Temperature Environments
Characteristics of Copper
High Electrical Conductivity
Copper’s low electrical resistivity at room temperature (20°C / 68°F) allows it to conduct electricity efficiently. It is ideal for power transmission components and electronic device electrodes. As temperature rises, resistivity increases slightly, but copper still outperforms most metals.
Resistivity at various temperatures [μΩ·cm]:
0°C or 32°F: 1.55
100°C or 212°F: 2.23
300°C or 572°F: 3.6
700°C or 1292°F: 6.7
*Resistance [Ω] = Resistivity [μΩ·cm] × Length [m] / Cross-sectional area [mm²] × 0.01
High Thermal Conductivity
Copper’s thermal conductivity at 20°C is 372 W/m·K, higher than aluminum alloys (236 W/m·K). This enables efficient heat transfer, making copper ideal for cooling and heating components like heat exchangers and heat pipes in satellites. Heat pipes help to balance extreme temperature differences in space and prevent overheating during re-entry.
Electrical and thermal conductivity in metals are closely correlated, so copper excels at transferring both energy forms.
Non-Magnetic
Copper is completely non-magnetic, making it suitable for sensitive electronic devices where magnetic interference must be avoided. Copper alloys are often used in geomagnetic instruments to maintain accurate readings.
Usable in Extremely Low Temperatures
Pure copper resists brittle fracture even at extremely low temperatures while retaining high electrical and thermal conductivity, making it suitable for structural components and heat exchangers. Copper alloys with impurities have slightly reduced conductivity under cryogenic conditions.
Types of Copper
Copper is divided into pure copper and copper alloys. Pure copper (≥99.9% purity) offers maximum electrical and thermal conductivity. Copper alloys trade some conductivity for improved properties like rigidity.
Oxygen-Free Copper (C1011・C1020)
Oxygen-free copper contains almost no oxygen and is the highest purity type of copper. It has excellent conductivity and machinability and is resistant to hydrogen embrittlement caused by high temperatures.
Tough Pitch Copper (C1100)
Tough pitch copper is slightly lower in purity than oxygen free copper. It is more cost-effective and maintains high conductivity. However, it is not suitable for high-temperature heating, welding, or soldering above 600°C (1112°F) due to hydrogen embrittlement.
Deoxidized Copper (C1201・C1220・C1221)
Deoxidized copper has had oxygen removed to prevent hydrogen embrittlement present in tough pitch copper. It has slightly lower conductivity compared to tough pitch copper.
Beryllium Copper
Copper-beryllium copper improves tensile strength and spring properties, and is widely used for conductive spring material.
Phosphor Bronze
A copper-tin alloy with phosphorus added to remove copper oxides within the alloy. It has high tensile strength, good spring properties, and strong resistance to chemical corrosion.
Brass
A copper-zinc alloy with over 20% zinc, increasing hardness and corrosion resistance. When reacting to oxygen, it forms a dark oxide layer that protects the interior. However, polishing restores its bright luster, making it suitable for decorative items.
Step Up Your Project with Yumoto Electric
Yumoto Electric delivers high-quality components fast, worldwide. We provide precision machining for a wide range of metals using milling, turning, and specialized metal processing. We have experience with over 200 materials including aluminum alloys, stainless steel, molybdenum, and titanium.
If you’re unsure about material selection or machining methods, we offer complimentary consultations to help optimize your design and production. For any questions, please feel free to contact us.
