Yeah, I sent a hacksaw blade through my finger while trying to saw a part off of a sprocket which I had held in a pair of mole grips (didnt have a vice or anything else) - wasnt the smartet thing I ever did. Also achieved a similar effect with a Dremel tool with a circular saw blade fitted - again I was holding the workpiece in my hand (maybe I should really consider getting some sort of clamping device now)