... /60mm,42/65mm, Sinter Diamond Drill Use for Drilling machine ,it can make hole for downc Diamond drill bitsDiameter ... :40/60mm,42/65mm,Sinter Diamond DrillUse for Drilling machine ,it can make hole for downcomer, Smooth cutting surface ... 2mm,10.5mm,12.8mmApplicable Machine: Protable drilling machine,Fixed drilling machine,PC drilling machine,Back bolt drilling machine.High quality wilt super performance ...