... diameter 3.Hammer drill 4.Deep depth&high efficiency bore well drilling Features:(1).Percussion type drilling rig is ... than the other kinds of drilling machines.Meanwhile,when use the percussion drilling rig to drill boreholes,after the ... soil,sand,pebble or rock into pieces,and then use the slag tube or mud pump to clean the ... Hoist(N)Front hoist20096 High efficiency ! AKL-A-6A, bore well drilling