Aluminium Question

Hi guys, so i decided to try out milling some aluminium, the outcome was not too shabby for a first try. But now im a bit concerned if i dulled my end mill or im just not that familiar with machining in general. Here’s some pics of the machined piece and the end mill. Btw, i have no idea which type of aluminium this is, its a 1/2inch bar.

EDIT: The endmill is Carbide (TiAlN Coated)


Yeah, that bit definitely appears to be blacked and probably got a bit too hot. Try cleaning it (with spirits, acetone, etc) and see if it comes off.
Maybe it can be salvaged?
Otherwise its a learning experience!
Slow down your spindle speed?

I have the same bits…they start out nice and black. :slight_smile:

@JeremyJohnstone thats the TiAlN coating, what concerns me is not the black but the lack there of on the cutting edges.
@ErikJenkins yeah, hey look awesome :smile:

Part of you issue is that this is a 4 flute end mill… 4 flute end mills are meant for materials like steel and are not good in softer stock like aluminum, A 2 flute or 3 flute end mill is best for aluminum work. Aluminum is soft and needs a larger space in the flute to chip off. A four flute end mill does not allow the proper space for a good chip to form in aluminium. You will get a far better finish ( almost mirror like ) with a 3 flute end mill like at Viper from Destiny tools. A good 3 flute end mill will cut many jobs before needing to be replaced and if you use something like G wizard (though slightly adjust the settings due to how flimsy the XC is) your end mills should last for a long time. You finish should look like these right off the mill when a good 3 flute end mill is used.


@Travelphotog thanks for the info! I have a 3 flute end mill that i haven’t tried yet. I get all my end mills from Torbide Tooling, i also have 2 flute ball ends with TiAlN coating that i want to try for alum but im not sure a coated tool is the way to go.

More often than not a coated tool is the way to go for milling almost anything. You can have a read here and get a good idea of which coatings are best for which type of stock. Dry milling of aluminum you will need all the help you can get and make sure you have a good chip clearance system in place or you will face many issues trying to dry mill in aluminum.

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@Travelphotog thanks for the tips! I have the dwp611 which blows air like a compressor and a dust shoe that picks up pretty much every single chip :smile:

This is very good information many thanks. One question would be what travel speed you use for aluminium @Travelphotog ? How deep goes the Z axis on each step down? I am also using a dwp611 do I need to refrgerate manually every step down too?

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@ElReactor i use these settings for my 1/4" 3 flute end mill:
Surface Speed: 319.186 m/min
Cutting Feed: 2500mm/min
Ramp/Plunge Feed: 800mm/min
DOC: 0.25mm

EDIT: also, last few cuts i made it tried 3in1 oil, it works like a charm, but without the dust shoe the mess was insane to clean up.