Barely able to cut 16 gauge flat sheet of mild steel (1.4mm thick). It survived a very rough couple of inches with harsh vibrations and then gave up completely, perhaps due to the cutting head becoming blunt. I've tried holding it at different angles and using slower and faster drill speeds to no avail. The box seal says it can handle 1.5mm or more steel, but I find that claim unlikely based on my experience. It may work better with thinner and/or softer material, but I don't think it works as advertised.