Borehole Drilling Method

power auger

notation 1.2 more like this
definition Mechanically-driven auger drilling, typically used in hard ground or for holes that are too wide or deep for hand auger drilling. Auger drilling is done with a helical screw which is driven into the ground with rotation; the earth is lifted up the borehole by the blade of the screw. Small power augers can be portable or mounted on the back of a utility truck, with larger auger rigs used for construction, like sinking piles for bridge foundations or mine shafts. more like this
source more like this
broader auger
narrower power auger
in scheme boreholedrillingmethod
is primary topic of power auger