View Full Version : help needed boring 8mm holes 20mm depth in Alu

22-04-2016, 08:51 PM
Hi everyone, I'm kinda stuck trying to do boring operation on my Alu plate, I have used initially 3/16 inch 2 flute carbide end mill with speeds and feeds recommended by hsmadvisor/Fswizard and what happens is that either spindle overloads and everything halts or noise is so bad and I stop it, just to find out the alu got stuck in big pieces in the flute channels! scary and I had to remove them with pliers. tried a 6mm ball nose carbide end mill hoping that since it was higher quality it would cut okay, still same issue and alu would gum in the end mill a bit and noise and everything just isnt right. probably because of the aluminium getting glued to the end mills haha

what do I do? is using 2 flute end mills wrong? is the size wrong? I have a 2mm 2 flute end mill but I wouldnt be able to get it all the way down to my required depth due small length and shaft being bigger than 2mm.

please appreciate your guidance on how to proceed

22-04-2016, 09:45 PM
Try a single flute cutter, I've had excellent results with 2mm, 1/8" and 6mm single flute cutters in aluminium alloys.

22-04-2016, 09:47 PM
I use lots of air to clear chips and a bit of WD40 now and then to stop the chips sticking to the cutter BTW

22-04-2016, 09:57 PM
You need to get chips out the hole, and lubrication in.
Without either of those, it's not going to end well in deep holes!

23-04-2016, 08:48 PM

24-04-2016, 07:05 AM
thank you , used a single flute bit to do it, it wasn't meant for alu I think only for alu but it got the job done

24-04-2016, 01:27 PM
The 1/8" single flute bits I use for Aluminium alloys, brass and bronze are advertised for engraving and plastics use, I sharpen them with a little more relief and I've yet to have one chip or break, attached is a photo of a prototype linear tracking air-bearing tone arm I profiled from solid with a 6mm uncoated single flute bit, air to clear chips and a little squirt of lube every few passes and the bits just keep on running,