https://forums.autodesk.com/t5/machining-discussions-forum/thanks-and-more-questions-on-tool-deflection/m-p/6097061#M8417 For aluminum, I like to use the 3 flute aluminum specific end mills.&nbsp; Like this one:<BR /><BR />http://www.ebay.com/itm/281532519298?_trksid=p2060778.m2749.l2649&amp;ssPageName=STRK%3AMEBIDX%3AIT<BR /><BR />It's amazing how much better these work than conventional 2 flute endmills, and they don't much more.&nbsp; They also work great for plastics.<BR /><BR />C| Thu, 22 Jan 2015 17:49:53 GMT kb9ydn 2015-01-22T17:49:53Z