I have used it for metal, but once you use it on metal you kind of ruin it for wood (the paper disc, not the machine.) I'm not sure if it's kosher, but it does polish flat pieces rather nicely. It's not like one of those knife belt-sanders that are specifically made for metal. Probably the type of belt/disc you put on it makes a difference too. I just know it's there, I'm lazy, and belts/discs are disposable. But now that I'm hooking it into the dust collection I will stop using it as a cheap grinder because I don't want to suck hot metal dust into a bag of wood chips and start the next great fire to burn half of Arizona.
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