I've used the standard grinding discs successfully on aluminium, but I suspect there is a better choice than this if you want to get a nice finish and do it properly. What kind of thickness are you trying to cut?
Same. Mine came with a can of 30 standard cutoff wheels. I have had no problems taking my time cutting 1/2" bolts with them. When you deal with thick bolts, you have to go around it..Sheet metal, 1mm thick, easy.
I've tried using the included '540' model discs. They do cut through the aluminium, although rather slow. Those discs are very thick though (2 to 3 mm). As i just want to cut one piece of another, i feel like i'm grinding away much more material than required.
I don't think you need a fiberglass reinforced wheel for some aluminum. Try the 409 15/16" cutoff wheel. The fiberglass reinforced disks are still pretty thick, these disks are almost paper thick. They are also a little harder than the fiberglass disk, so they wont get clogged with aluminum as easy.
Interesting - i'll order some of those and see what they do.
The stuff i'm trying to cut isnt exacty sheet metal though - its aluminium profile thats about 3 mm thick. I'm not sure of the exact alloy - i'm sure its mostly aluminium, but as these profiles are intended to finish window/door frames and such, they might be quite a bit thougher than pure aluminium.