Abstract: Apparatus is disclosed for guiding a metal cutting torch to enable the flame thereof to cut a controlled thickness of metal material from the length of the outer surface of a elongated hollow cylindrical workpiece mounted securely to a shaft extending therethrough to enable the wall of the workpiece to be severed. A carriage for holding the cutting torch is slidably supported for movement along the length of the workpiece when the apparatus is mounted on the workpiece. The apparatus includes a feeding device for advancing the cutting torch at a controlled rate to enable the cutting torch to cut away substantially all of the thickness of a length of the workpiece, thereby weakening the workpiece sufficiently to enable its wall to be severed.