... button bit, rock drill bit,Retrac Button Bits,taper drill bit,tapered drill rods,taper button bit thread button bit, rock drill ... bit,Retrac Button Bits,taper drill bit,tapered drill rods,taper button bitDiameter :40 mm -200 ... mm (D)Bit Type: Button Bit, Cross BitButton Type: Hemispherical, Ballistic ...