When drilling 6160 aluminum I started small to open up the hole enough to use a medium sized bar. I had about 65mm of overhang, which is a bit too much. Even the slightest pressure would bend the thin rod. I felt like I could bend it with my fingers. As with the medium sized bar, I have to go through the hole twice as the bar will flex away from the aluminum even with a moderate overhang. When you come back out of the hole, you really notice that the cutter cuts a lot more when you pull it outβ¦