Diamond drill bits Diameter :40/60mm,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,high cutting speed.Diamond drill bits for stoneSinter drill bits :Mainly used for granite, ceramics, concrete ,quartz stone ,and other ...