Originally Posted by
robobass
Old thread, but first, how deep are you cutting? Why are you buying stock from HD? You can get better alloys online for cheaper. I would never try to dry-cut 6061 with a high speed spindle. I don't know what it is called in North America, but I use "Al Cu Mg Pb - F34/37 EN AW-2007" which has lead content making "dry-cut-able". I run passes no deeper than .5mm at around 350mm/min. Carbide is good, but TIALN or TICN is probably the best for this. More expensive than HSS per endmill, but orders of magnitude cheaper per job. I mostly cut brass dry with both TICN and Carbide. Some of my endmills last for years.