These tools have been designed to remove the external bead from a butt-fusion welded joint. The tool knocks on to the pipe bead, then alignment blocks slide against the pipe surface to guide it around the pipe. They have a blade that cuts under the bead, but does not damage the surface of the pipe. A handle helps pull the tool around the pipe, cutting the bead away. These tools are fully approved to the UK National Grid specifications GIS/PL2-5 and have been accepted for use on their gas networks and pipes.