Carving aluminum

Today i broke my own record I snapped four 1/8 inch single flute bits trying to carve aluminum. I started at 100 IPM and kept cutting the rate and plunge in half. I know I know, why would anyone carve aluminum well because I did not want to use my manual mill to do the same part over and over again. Well I finally determined that I needed a heavier duty bit, and a four flute 3/16 bit did the trick. ipm:70, plunge rate 35, pass.030 on a .188 diameter four flute .250 shank HSS end mill. So, if you are doing any aluminum these are a few settings that seem to work. I start again tomorrow so stay tuned for updates. If you have any experience carving / milling aluminum, post it here and we can learn from each other that way…


I’ve been too afraid to try my O flute bit on aluminum yet, works great on acrylic though :stuck_out_tongue:

Robert - I have successfully performed several cuts with the Amana 51454 O flute bit in 6061 aluminum. The pic here shows my settings.


rstrawsi: the pic shows feedrate of 18ipm and a plunge feed of 30ipm. Is that correct? It seems backwards.

thank you for that info. this is why the onefinity forum is the best. Users helping one another.

I have been afraid to try my O-flute bit on acrylic. Some people run 10,000-12,000 while others run 18,000. Would you give me a hint on your feeds and speeds for acrylic??? I would really appreciate it.

I used a 1/8" diameter bit, 18kRPM and 90ipm. I think I just used this chart when creating the settings.

ok todays results in aluminum my 4 flute 3/16 dia. HSS bit cut 11 parts perfectly but then on number twelve it suddenly started screaming. when i stopped it it was not broken but the flutes were filled with melted aluminum. I am supposing the bit got too hot and once that happened all sorts of bad things happened. so, my next move is to get a 0 flute amana bit 3/16 up cut and try again. this one is especially made for aluminum so perhaps it will work better. i am also going to hook up an air blast to both blow cold air on the bit to keep it cool and blow away the chips as well
. wish me luck the bit gets here on wednesday.

Oh and not to be too picky this thread is for aluminum cutting not acrylics, i would not want anyone reading down the thread and get confused by the different numbers for acrylics and plastics when they think it is for aluminum. Just asking.

1 Like

Fully agree - Point taken (-:

Thank you for the information. I was hoping the speed would be more like 12,000 rpm because the router runs quieter…

If you decrease the RPMs by ⅓ you could also decrease the feedrate by ⅓ as well and you should get the same chip-load, it’ll just take longer.

Should probably create a new topic if you have further questions so we don’t continue to hijack this thread though :slight_smile:

1 Like

Thank you for the link. I looked at it and wrote it down. Now I have to convert it from MM to inches. Thank you.

I did notice what I think is a mistake.

In the 2D pocket part you gave and rpm of 1,800 and I think it should be 18,000 rpm

Thank you for the info.


You are welcome (sorry but I prefer to work in metrc). Thank you for highlighting the error - I very much appreciate it. I have corrected the video and made a note of the error in my Onefinity CNC Advanced Users Group FB post, which is where I moved my post.

I have yet to use aluminum on my 1f but I have spent years cutting aluminum. Clearing the chips is the biggest problem and a four flute can’t do that. You did not melt the aluminum you just couldn’t get the chips out fast enough so you crammed the chips in between the flutes. One or two flutes is the best for aluminum.


thannks yep that was a problem lol

Curious, how does everyone handle the chips when cutting aluminum? Also, do you use lubricant or air mister? My main concerns are metal chips getting into the bearings or other moving parts!

Try using high speed machining methods, very light depth of cut, .007" or so, and the 100 ipm might work. It is dry machining though, i don’t ever do that on aluminum. I’ll mess around with it, be nice if it will do it with a decent surface finish. WD40 is aluminums best friend in a lot of manual machine operations, might help a lot. Aluminum sticks to tools otherwise

I pretty much only cut aluminium. Solid Carbide Single flutes are the best. With a single flute you can rough at 90% stepover, 12.5% stepdown, 0.1mm chipload @30krpm, puts the feedrate at 3000mm/m. I like to use 3 flutes for finishing operations. I’ve got an air blast setup so it blows the chips away from the cutter

1 Like

thank you now that was very helpful i did receive the 0 flute bits today and used them well. One of them at least so far is so good I have yet to set up the air blast, though maybe tomorrow.

I’ve not done aluminum on the Onefinity, but will second the WD-40 after 30 years of using on manual machines. Although technically not a lubricant, it acts like one and also makes a good coolant.