LynnC,
They will cut most metals and the large teeth don't load up with soft metals like lead, babbit, aluminum, copper, etc. They work great on hardwood but if they are not sharp, they will skate over the surface. Mine were old and not too sharp but I sent them to Boggs Tool and had them sharpened. They work great now.......Come to think of it, I may have found a few of these at an old tool sale somewhere.