I use this tool to make some cuts in 7 inch sheet metal of .031 gauge aluminum and stainless steel. The tool works well but requires the use of a very specific tool. to make multiple cuts and move quickly around the sheet. I think it's better to keep it upside down. You also need to make cuts that aren't the full length of the blade to avoid small indentations at the end of each cut. The raw edge has some ridges, so if you want it to be perfectly smooth, plan for a little sanding.