I've had good results milling 6061 Al but wanted to mill some 3003 sheet stock (40 and 63 mil). I'm using 3003 because it bends fairly well and 6061 surely doesn't. It cuts but I'm getting a lot of burrs. The F&S and DOC that cut 6061 cleanly leave lots of jagged burrs on 3003. Played with feeds and speeds with faster feed and shallow DOC (10 mil) gives the best result but still lots of burrs. Both a single flute straight and 2 flute upcut spiral give similar results. Speed is as slow as I can go - 12K - I know it should be about 1/2 that. On the feed rate, my router seems to protest above 50 IPM even with a shallow DOC so I'm staying with that. I can clean up the burrs later so it's not the end of the world.

Any suggestion on a better bit or different approach would be much appreciated. I've seen recommendations to use 6061 with heat treatment to get it to bend. Not really wanting to go that direction though.