Poor finish quality with 1/16 end mill

I did a project today where I needed to use a 1/16" end mill to machine small pockets. I am using an uncoated 1/16" 3 flute end mill, and I’m having issues with a very poor finish. I’ve tried using the 2D pocket which sounded horrible, and then switched to the 2D adaptive toolpath on fusion 360 which sounded better but still has a ton of burrs on the edges. The material is 6063 T5.

Here’s my settings:
18 In/min
0.00035" chip load
0.003" DOC
0.020" Width
No coolant, but I have a constant stream of compressed air to blow away chips

I’m not sure if I’m doing anything wrong, but it seems like the end mill is ripping through the aluminum rather than cutting it. I tried switching it over to a new bit, and it did the same. When doing the main machining with a 3 flute 1/8" end mill, it cuts through the material flawlessly.

Here’s how the part’s supposed to look like, and how the part turned out

In alu i never managed to get proper finishes until i moved to single flutes.
Now the little nomad3 chomps away material, creating a beautiful finish in alu.
smaller 2 flute endmills just smear and ultimately snap for me.


I’ve had the same experiance as @pauketju with 2 flute bits. Clogging and terrible “cutting” if you can call it that. I use 1 flute bits and air blast (sometimes a 99% IPA mist) and get great results with 6061.

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Thank you for your advice! I will give single flutes a try, are you pushing 0.001” chip load for the single flute?

I have not calculated anything actually. But i have tried and failed quite a bit.
Until i ordered a ton of single flutes from aliexpress… Now i mostly break them while vacuuming the machine.
I can recommend Xcan and Dreamuniq if you can wait for some reasonably cheap and good carbide single flutes.

I would go:
1.5mm (ish 1/16") 20k rpm, 1500mm/m 0.15mm doc ish but not more.
3.1mm (ish 1/8") 20k rpm 2000mm/m 0.18mm doc- maybe deeper, or just faster.
Do not use these numbers… I am dumb.

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