Yeah, I come from more of a machining background. I was thinking of 1/4", 3/8", and 1/2". But, I bet a good 1/4" coated 3-flute without too long a cutting helix could do 8K. Hopefully, I 'll get to see in next month or so. My 2.2KW spindle should be here in couple weeks.

Thanks,
Wallace