... ,42/65mm, Sinter Diamond Drill Use for Drilling machine ,it can make hole for downc Diamond drill bitsDiameter :40/60mm,42/ ... ,it can make hole for downcomer, Smooth cutting surface,high cutting speed.Diamond drill bits for stoneSinter drill bits :Mainly used ... stone . Diameter:4mm-200mmAnchor bits/Elecroplate back bolted drill: Single layer and double layer . Diameter 10.2mm,10.5mm,12.8mmApplicable ...