... drilling into clay, sand, bed, rock ,basalt, strata and more Contact online:Yahoo Skype and google talk ID ... process method, can be in clay and sand layer, rock and so on the many kinds of strata ... torque, driving fast, it is suitable for irrigation and water conservancy engineering, industrial deep well, national ... strong, can be in clay, sand, strong Weathering, bedrock, basalt and so on the many kinds ...