Technical parameter as below Model ZGYX-421TA Engine model Yuchai YC6J220 Engine Power 162 kw Drill pipe size 60 *3000 mm Hole diameter 80-115 mm DTH hammer 3.5 inch Rotation torque 1650 N.m Rotation speed 0-110 rpm Working pressure 14.5 bar F.A.D 12 m³/min Tramming sp...