SO3 First cuts in Aluminum

After a great deal of thinking, researching and navel gazing today I made my first cuts in Aluminum.

New photo by Andrew Hood

The material was 0.25" 6061-T6. The test cut was a 0.125" 3 flute ZRN coated carbide endmill (ebay $15 with shipping) cutting a 0.150" slot with a conventional cut 0.040" per pass at 22ipm with 7ipm plunge. There was a full depth 0.005" finishing cut, but it was too shallow to make a visible difference. The cut was very clean at the 6pm and 9pm position on the cutter and rough at the 12pm and 3pm position.

The fourth try was a bit better.

New photo by Andrew Hood

I increased the overall slot width to 0.205" with the rough cut 0.145" wide and a full depth 0.030" finishing pass. The rough cut was the same as before. The finishing pass was a 17ipm climbing cut.

I want to say thanks to G-Wizard. The tutorials and CADCAM wizard were very helpful in my making sense of all the options.

I used Fusion 360 for the model and CAM. My SuckIt dust boot did a remarkable job of keeping the area clean.

The rough pass still looked rough, so I thought maybe I should try a climbing cut. Not a good idea:

New photo by Andrew Hood

Proceeded to cut rough until the bit was clogged with AL (sorry for the poor focus, but you get the idea)

New photo by Andrew Hood

I managed to pry the Aluminum off the end mill and it appears to be cutting fine. It turned out to be an inexpensive lesson.

This was just a test cut. Next step is to rework my first Aluminum project to cut a wider slot and then see how it will work.


Rather than risk damaging the endmill, (assuming compatible coating chemistry) one can use a suitable chemical solution to clean off the aluminum — lye is the usual suggestion, and is easily sourced as drain cleaner.

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Good on you for trying. It is nerve racking to try aluminum. Are you using any kind of lubricant?

No lubricant. Counting on the coating to keep the Aluminum from sticking. If possible I would like to avoid the mess.

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I understand, but I think a little WD-40 goes a long way. I learned and follow the example of the other folks here who do way more aluminum work than me.

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Switch to a 2-flute end mill, and a spritz of wd-40 will do wonders for your finish.

Aluminum tends to “smear” so a decrease in spindle speed and slight increase in feed will get better results. Expect noise… lots of noise.

Personally, I use a jet of air to keep the chips clear. It’s very easy for a spinning end mill to get those fine chips to a malleable temperature, thus the smearing and sticking.

Good luck!!


try trochoidal milling (it can be done in Fusion 360) in Estlcam, gives excellent results in aluminium!

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I have had great results with an “0” flute. The high rpm of our routers hinders good results with more than 2 flutes without serious compromises in performance.