Quote Originally Posted by Snapper View Post
Is that end mill coated? Looks like it might have tialn coating, which will cause build up pretty quickly, that's probably not erosion but almost certainly a build up of aluminium on the cutting edge. You want uncoated cutters really for ali. And yes find out what the material is, even different batches of the same grade can cut differently but stuff like 1 series ali is horrible for machining.
OK, I'll get a 2 flute uncoated from APT and see how it goes. The cutters I have are coated but I don't know what with.

The part I was machining is the bed of the machine, so no idea what grade it is. I just wanted it flat(er) and level.

Once I get the new 2 flute cutter, is 6k rpm and 500mm/min, dry, still in the right ball park for taking a shallow finishing cut at say 90% engagement?



Just for my own interest, if there is build up on the tips of the cutter, how does that erode the tip?


Thanks for the input!