Paul is quite correct: most metal cutting blades have 10 tpi or more, and especially for cutting sheet metal you would want more like 16 tpi or more. Also, metal cutting speeds are much lower than wood cutting speeds.
I have a metal cutting bandsaw with 3 gears, and in highest gear with the coarsest blades I have (10tpi) I can cut wood OK, but it's no comparison to a proper wood bandsaw.
In an emergency situation this may work, but I wouldn't recommend it, and if you do it, feed the sheet in very carefully, otherwise you'll rip teeth out of your blade.