I'm using High sulfur black oil, chips are similar to what I have in my band saw, very small particles.I see no build up. Kerf on the OD is very small but inside is very large yet very fine whiskers. However that being said the first 3 cutters worked great at 47 RPM .5"/min feed rate .070 depth of cut total 2 in cuts .140". I measured the best I can with a digital caliper the flute depth of one of the 72 teeth, it's about .078". To avoid dragging on the cut during the return I drop the table so cutter is not in the slot.