... drilling and engineering geological drilling, etc.FeaturesPowerful;Top-drive head driven by hydraulic, stepless speed ... to move;With rotary support;Longer stroke of top-drive head, reduce auxiliary operation time;Compact ... /hClimbing capacity 20°Rotation speed of top-drive head (r/min)high 0-240r/min;low ... 0-80r/minStroke of top-drive head (mm) 3500mmRated pull force of top ...