Can a CNC router cut brass? ⚙️

Yes, a CNC router can cut brass, a non-ferrous metal that is relatively soft and machinable compared to harder metals like steel. However, achieving clean, precise cuts in brass with a CNC router requires careful setup, the right tooling, and optimized cutting parameters.

Guidelines for Cutting Brass with a CNC Router

• Tool Selection

  • Use carbide end mills specifically designed for non-ferrous metals. These tools typically have 2 or 3 flutes and a high helix angle, which improves chip evacuation and helps prevent material buildup on the tool.

  • Fewer flutes reduce heat and friction, leading to smoother finishes and extended tool life.

• Feed Rates and Spindle Speeds

  • Brass requires slower spindle speeds and relatively faster feed rates to prevent heat buildup and avoid work hardening.

  • A good starting point is to set spindle speeds lower than what you would use for softer materials like aluminium and adjust based on tool performance and cut quality.

• Chip Evacuation

  • Efficient chip removal is essential when cutting brass to maintain a smooth cutting process. Use a vacuum or dust collection system to keep the work area clear of chips and avoid tool clogging, which can cause poor surface finishes and tool wear.

• Rigidity and Stability

  • CNC routers vary in construction, and not all are suited for metalwork. Ensure your CNC router has the necessary rigidity and stability to withstand the cutting forces associated with brass machining.

  • Heavier, industrial-grade CNC routers handle brass cutting more effectively, whereas lighter machines may experience vibration and deflection, affecting cut quality.

• Lubrication and Cooling

  • Brass typically generates less heat than harder metals, but using a light coolant or lubricant (e.g., a mist coolant or cutting oil) can reduce friction, extend tool life, and improve finish quality, especially on deeper cuts or prolonged operations.

• Cut Depth and Passes

  • Cutting brass in multiple shallow passes rather than a single deep cut can help maintain control, reduce tool load, and achieve cleaner edges.

Final Considerations

While CNC routers can cut brass effectively, they are generally optimized for softer materials like wood and plastics. For extensive or high-precision metalwork, or when working with harder metals, a CNC milling machine is typically the better choice. CNC milling machines provide greater rigidity, power, and control over cutting parameters, ensuring higher quality and durability for demanding metal-cutting tasks.

By following these practices and adjusting for brass's specific requirements, you can successfully machine brass on a CNC router while achieving smooth, precise results.