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<aside> 🔖 Meta Description Can a CNC router handle copper? Yes! Learn the essential spindle speeds, tool choices, and cooling hacks to machine copper without the gum.
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CNC routers are typically associated with wood and plastics, but they can also handle non-ferrous metals like copper, aluminum, and brass.
While not the most efficient option for large-scale metal production, routers offer a cost-effective solution for small-batch copper parts, especially if you already own the equipment.
This guide covers everything you need to know about cutting copper with a CNC router: from understanding copper's properties to step-by-step machining techniques and real-world applications.
Copper is a ductile, malleable metal that conducts heat and electricity exceptionally well.
Unlike most metals, it has a distinctive reddish-gold color that oxidizes to green when exposed to air and moisture, the same process that gave the Statue of Liberty its iconic patina.
Copper's key properties for machining are:
Electrical and thermal conductivity: Copper ranks among the best conductors, making it essential for electrical and heat-transfer applications. About 75% of copper produced globally goes into wiring and electronics.
Malleability: Copper can be shaped into sheets or stretched into wires without breaking, which makes it versatile but also challenging to machine. It tends to be "gummy" and can stick to cutting tools.
Alloy versatility: Copper forms useful alloys with other metals. Brass (copper + zinc) and bronze (copper + tin) offer improved strength and durability while maintaining many of copper's beneficial properties.
Material grades: Different copper grades have varying properties. C145 tellurium copper, for example, is heat-treated to a full hard state, making it easier to machine than pure copper.
While all copper is conductive, not all of them are compatible for spindling. A "gummy" pure copper can snap a bit in seconds, whereas a free-machining alloy will produce clean, crisp chips. Use the chart below to identify which grade fits your project’s balance of conductivity and machinability.
| Copper Grade | Name | Machinability Rating | Key Characteristics | Best Use Case |
|---|---|---|---|---|
| C14500 | Tellurium Copper | 85% (Excellent) | Added tellurium makes it "free-cutting"; breaks chips easily. | High-speed CNC routing/milling. |
| C14700 | Sulfur Copper | 80% (Great) | Similar to C145; high conductivity with good chip control. | Electrical components and connectors. |
| C36000 | Free-Cutting Brass | 100% (Reference) | The easiest copper-based alloy to machine. | High-volume small parts/fasteners. |
| C17200 | Beryllium Copper | 20% (Difficult) | Extremely high strength; requires specialized safety tools. | Aerospace and heavy-duty springs. |
| C11000 | ETP Copper | 20% (Challenging) | Very gummy; "sticks" to bits; high thermal conductivity. | Bus bars and general electrical work. |
| C10100 | Oxygen-Free Copper | 20% (Challenging) | Purest form; highest ductility; prone to tearing. | High-end audio and vacuum electronics. |
Yes, but with important caveats. CNC routers can cut copper effectively for certain applications, offering several advantages: