metal lathes usually have a 3 or 4 jaw chuck to hold the work piece in place rather than the dead center with sharp edges to grab the wood. And metal lathes dont have a tool rest for the lathe chisels but im sure if you have a metal lathe you have the know how to fabricate something to substitute. ps.. some metal lathes can reach speeds of 4-5 thousand rpm. personally i have a small tabletop metal lathe and a 48inch wood lathe. and i try to keep the workpiece to its designated machine.
-Chris