Milling Aluminium Help

Afternoon all

I’m working on a proper aluminium project now - in the past I have only used 3mm thick aluminium and I’m jumping up to 15mm bar and I’d really appreciate some advice.

Here is my project in fusion 360:

as you will see there is a number of holes in it that are 6.5mm wide. For the entire project I want to use 1 4 flute 6.35 cutting piece - however I don’t know what settings would be best to use to achieve a good result.

Any advice would really be appreciated on feed and cutting / plunge/ depth rates.

the current model settings are for wood as I wanted to make a test model.



I had my first go at this - I used a 300mm a min cutting feed rate and 0.2mm off - I got ok results but not great.

Tomorrow I’m cutting down to 0.1mm and 600mm a min.

Will still take 3 hours - I figure double the speed, half the cut…

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If you haven’t seen the wiki, we have some information on the wiki, including the official Carbide 3D numbers:

(the original chart for that is at: )

Thanks I did allot of reading and had a couple of goes at it last night/today.

I had reasonable success going at 1500mm a min and 0.1mm cuts. It went well till I got to the small holes where the bit got gummed up about 4 holes in. This had ramifications later when it welded it’s self to the bit.

I think next time I will use a 1/8 drill bit to pre drill the holes then mill them as a 2nd pass to reduce the load.

I managed to salvage the piece it did need more tlc by hand but a good learning experience.

Here is a pic pre paint after orbital sandi