If you mean do they remove metal? Yes they do. But there might be a tendancy to remove too much. Most guys who can't sharpen don't maintain a consistant angle of the blade to the stone. My opinion is that you'd be better off with an adjustable manual system like Lanski or GATGO that clamps the blade into a guide that fixes the sharpening angle. Different knives have different sharpening angles. It allows you to use varying grades of stones to sharpen or just touch up a blade