Quote Originally Posted by Jonathan View Post
Those cutters are advertised as:

'For ultra high speed machining of high hardened materials.• Suitable for dry cutting and high speed cutting.'

So they're meant for machining hardened steel without coolant at a high speed ... nothing to do with machining aluminium.
These are the cutters I use for cutting steel and they work great with my WC spindle at 10K and last ages but I have tried them on Alu and they don't like it no matter the speed & feed. I've tried all combinations deep DOC + slow feed high rpm and vise versa etc and which ever way they just don't like Ali.? . . . Not surprising really has there not designed for it.!

To be honest I find the Alu pow HSS 1 flute give a great finish, better than carbide, but they don't last long enough.