Quote Originally Posted by pat mccarthy View Post
it still running spins to fast for alum yor will have a hard time keeping the carbide from loading up
Spray WD-40 on the bur and it won't load up. High speed or carbide.

I have been using 1/8", 1/4" (with & with out a flex shaft, & 90 dgree grinders every week on alumumn & steel/iron since early 70's I have top of the line name brands, and I have grinders that I paid $14.00 for, the old Dremel worked & last the best.
The only 1/4" one that I burned out was a Chicago electric, 3-5 mins after I started use it! still use the replacement one on lite stuff.

I have changed many brush's in all brands I've owned. Harder to get name brand brush's, alot of cheaper ones come with spare brush's. I work them hard most of the time when I use them.

Pat