A tool for shortening an implant rod has a base housing part and a movable housing part shiftable toward and away from each other in a predetermined direction. At least one guide roller is provided on the movable housing part, and a cutter is provided on the base housing part. The rod is fittable between the cutter and the guide roller in a spread position of the housing parts. A biasing unit urges the parts together and thereby presses the cutter into the rod with a predetermined force. Thus the cutter is pressed against the workpiece with a force that does not change and that is not under the control of the user, ensuring that the force applied lies within an acceptable safe range.
