... air pressure:7-21bar 3.good improved function QZL100B-M1321 DTH anchoring mining drilling rig1.easy to operat machine2.air ... of drill machines and drill equipment in China.Such as DTH drill rig,water well drill rig, Trenchless Horizontal Directional ... Drilling Rig,drilling rod,drill bit,DTH hammer,etc.technical parameterDrill diameter: 68~100mm(fit Φ50mm drill ...