I rarely run anything besides steel so I'm not sure what the best approach is with this. I need to hog out a bunch of material in UHMW plastic, about 2" deep. My first thought was to use a square shoulder inserted shell mill making 1/4" deep passes, but I also have some 1" HSS end mills that I could run at full depth. Or maybe a fly cutter? What's the best way to go? I'm not sure if carbide inserts will "weld" to the plastic if the speed is too high?