Single flute ball endmills for aluminum?

I’m looking at dipping my toes into aluminum machining on my Shapeoko 3XL.

Based on all I’ve read and watched, single flute end mills look like the go-to solution. However, most of the single flute end mills I see (including the ones that Carbide3d sell) are normal flat end mills. To get a decent finish on 3d parts I’ve been looking for single flute ball end millls, but they seem rather rare.

What are people using?
Does anybody have european sources for these?

I found some at Sorotec, but none that are ZrN coated:

I’ve got away with regular 2 flute ball endmills in Aluminium so far, the standard Carbide 3D 1/4" and some from APT

I run a roughing cut with a single flute first leaving ~0.5mm on the piece then come back with the ball nose. I keep the dust boot on and run extraction the whole time to help clear out the chips but I don’t have an air blast or lubricant.


I agree with Liam, a common scenario is using a single flute to do the roughing part, and then switch to a 2-flute ball endmill for finishing the curved sufaced: since finishing removes very little material, and probably not in bottom of deep slots anyway, as long as you have good chip evacuation (a jet of air or dust collection in place) there should be no problem at all using a 2 (or 3) flute ball endmill.

I remember using a 3-flute #202 ball endmill for finishing in some of my early aluminium experiments, not a particularly great example of a good finish, but just for illustration.

I also remember someone recently commenting that they did not really like their rare single-flute ball endmill, but I can’t find that thread right now.


That someone is me. I used a single flute ball from Datron on my salt and pepper shakers that I entered into the latest contest. Since single flutes are usually not balanced they can cause vibration, especially with the big ones. Vibration is your enemy when you are doing finishing toolpaths which is what a ball endmill is mostly used for. 2 flutes for finishing in aluminum will work great. Just be sure to keep your chipload high enough. Chip thinning can play a big factor here as well.


That someone is awesome. Well done Nick. Great project!