Can I cut aluminum on my CNC router, and how?

The honest answer

Yes, most rigid hobby routers can cut aluminum, slowly and carefully. Wood routers lack the rigidity and low-RPM torque of mills, so success means light cuts, correct chip load and lubrication. Flexy belt-driven machines will struggle, while screw-driven machines do fine.

What kills it: built-up edge

Aluminum's failure mode is chip welding. Too little chip load rubs, heats, and welds aluminum onto the bit, which then snaps. Like plastics, you must make real chips, but unlike plastics, the material fights back.

The recipe

The numbers below are community starting points, not figures from the official documentation. Test them on scrap and adjust for your machine's rigidity.

1. Alloy matters: 6061 machines well, so buy it. Avoid unknown extrusions and soft alloys (gummy).
2. Single-flute carbide bit for aluminum (or 2-flute), 1/8" to 1/4". A single flute compensates for routers' high minimum RPM by halving the effective flute count.
3. Chip load about 0.001 to 0.002": for example a 1/8" single-flute at 12 to 16k RPM gives about 15 to 30 IPM. Never slow the feed to "be safe", because rubbing is what breaks bits.
4. Shallow passes: about 0.1 to 0.3 mm (0.005 to 0.012") depth per pass on a small bit. Full-width slots are hardest, so prefer smaller stepovers and adaptive-style clearing where possible.
5. Lubricate: WD-40 or cutting fluid brushed or misted on the cut dramatically reduces welding.
6. Ramp all entries (never straight plunge), and clear chips constantly (air blast is better than vacuum, because recut chips weld).
7. Rock-solid workholding. Aluminum grabs, so use screws or serious clamps, not tape alone.

In the software

Nothing special is needed. Profile, Pocket, Drilling and engraving toolpaths all apply. Set up a dedicated aluminum tool-database entry with the numbers above so they stick. V-carving or engraving aluminum with a fine engraving bit works well for plaques (shallow, fast, lubricated).

Pro tips

• Expect noise and tiny sharp chips everywhere. Eye protection is non-negotiable, and keep chips out of your machine's rails.
• First project: engrave a plaque or cut a simple bracket from 6061 plate, not a deep pocket.