... for repairing, grinding, polishing, crystallizing millstones.diamond floor grinding machine HWG 70 has the quickest motor speed, from 300 rpm ... equipments. It is good for grinding and polishing in large area, and greatly consume time and labor.Performance:1, ... , maintenance.2, Polish concrete, marble, granite, terrazzo with various grit of diamond metal, resinbond.3, Remove painting, coating, epoxy, ...