... 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 ... available as per customers'request You can look the catalog page , which iterm number you are intrested ,then tell us .Thanks ...