Mill Brass & Aluminum with a CNC Router

Add a new dimension to your woodworking skills.

- Chris Fitch

With the right techniques and tooling your CNC router can mill brass and aluminum with dependability, accuracy and consistency. Milling these materials on a home shop CNC router isn’t difficult, but milling metal requires a different and a disciplined approach. Here is a basic formula to get you started:

1. Stick with easily machinable alloys.

2. Choose the bit that is correct for brass or aluminum.

3. Mill at an RPM and feed rate that is right for your machine.

4. Use a light depth of cut.

5. Lubricate the bit.

6. Clear the chips.

The Alloys

We want to choose an alloy that machines easily, is commonly available and is affordable. Aluminum alloy 6061 is a great choice to work with. Manganese and silicon are the major alloying elements. Alloy 6061 is strong, corrosion resistant, inexpensive and widely available and can be easily machined on a CNC router.

Ultra-machinable 360 brass consists of copper and zinc, and as you might guess from the name, it is made to be easily machined with the addition of lead. This attractive alloy stands up to high speed milling with minimal wear on tooling while generating chips that clear easily from the cut.

1 360 brass alloy material is excellent for CNC routing.

2 A two-flute bit (left) for brass and single flute bit for aluminum.

The Right Bit