A spiral saw bit that can cut through metal- up to 18 gauge steel- including but not limited to HVAC and steel studs. The drill bit tip allows for plunging directly into the work piece, which makes starting a cut much easier. For use with all Spiral Saws.Amazon.comThe Rotozip XB-MC1 Metal Cutting XBIT is the first saw bit that's built to cut through metal. This carbide-constructed high-speed bit cuts up to 18 gauge steel, and is ideal for HVAC, steel studs, aluminum siding and more. The 5/32-inch diameter bit tip allows for plunging directly into the work piece, which makes the start of cut much easier.