Hollow Hammer drill Carbide Tipped Core Drill bits Diameter:65mm Material: Carbon steel, Carbide: YG80C best quality Hollow Hammer drillWith hollow core, connecting rod ... sizes: 60mm, 65mm,70mm, 80mm, 85mm,120mm,100mmMaterial: Carbon steel, Carbide: YG80CAdyantage: open holes for air conditionswidely used in hard material ...