And they are VERY AGGRESSIVE! But they tool guy said if you even touch steel with them, it will take the edge off them.
Yes, they are aggressive, but I use mine to cut steel, too, a lot of the time. It doesn't seem to hurt them at all.
And they have the wide grooves in them so if I get a burr up my
ooops!!
.... I mean if I get aluminum stuck in my burr, I just use a small screwdriver to push it out!
Normally that doesn't happen, though, unless you get it too hot, or the burr is worn out.