View Full Version : End mill question

15-06-2009, 12:06 AM

I need to buy an endmill that is as flat as a pancake on the bottom surface...(I don't need it to bore, but need it to only 'cut' in a sideways direction) ....but there's a veritable plethora of end mills out there....& I'm confused!

What type of endmill should I be looking out for? (ie is a 'flat end mill' exactly that - flat bottom). How many flutes, etc? (it's for acrylic)


John S
15-06-2009, 12:18 AM
If it's for Acrylic get a 2 flute cutter, they will be called end mills or slot drills.
2 flute is better as with soft materials you need as much room as possible to get rid of the chips as they are usually cut faster than harder ones.

Acrylic tends to melt if run too fast in speed and feed, coolant is ideal or at least a strong air blast to stop it melting.

HSS is better than carbide as you can get a sharper edge on HSS

In a worse case scenario it melts and then re welds itself back again behind the cutter

06-08-2009, 04:29 PM
Sorotec has really good EM for acrylic at pretty good prices and I have no interest in said firm other than I use their tools.


23-09-2009, 03:31 PM
What you describe is essentially a 'centre cutting endmill' which is basically a slotdrill. The main problem with cutting plastics is heat generation through cutting. You want to keep the heat in the cutter and not in the material, so regardless of whether you use HSS or carbide cutters, supply a cold air feed to the cutting area, and don't be afraid of cutting quickly. Cut slowly and you run the risk of melting the plastic.

And as stated before, 2 flutes will clear your chips more easily.