Main problem with carving metal with a router is that the speeds are way too high. Wood, plastic etc. can be machined at pretty high speeds, but the harder the material the lower the cutting speed you must use. If some router can be slowed way down, probably to a thousand rpm or less, then it might cut metal, but you also need a very solid way to hold and guide the tool as metal cutting also requires more force than wood.
In sum, I doubt most routers will do well with metal, but it depends on the material, size of groove etc. Should you try it, be very carefull, you're more than likely to jam and/or break bits and have flying bits about that could blind you. Oh no, not that! Tom Fowle
