Special Line SGP tools are specially developed for specific tasks and offer the user key advantages over conventional products. Furthermore, the Special Line SGP includes tools that offer ultimate economic efficiency thanks to their particularly high performance during use. The patented flap disc POLIFAN-CURVE has been specially developed for work on fillet welds. It is the only flap disc in the world that has flaps on both the grinding side and on the rear side, as well as on the radius. Special flap disc for work on fillet welds on aluminium.