The drilling heads are are used for cutting the soil and are mounted on the face (start) of the auger with a hexagonal shaft according to table I “Hexagonal connections for augers”.
All heads are equipped with retractable wings increasing the diameter of the drilled hole in the ground above the diameter of the pipe installed. These wings open automatically at the CLOCKWISE turn of the drilling head and automatically close at the COUNTER-CLOCKWISE turn of the head. With the wings closed, the drilling head together with the entire column of augers can be withdrawn from the steel casing pipe, which remains in the ground.
Drilling heads, depending on their size (diameter) and the type of drilled soil, may have different designs. For work in light soils and embankments, knife heads (the so-called ordinary heads) can be used, while for works in medium and heavy soils it is necessary to use hardened heads with replaceable hard alloy teeth.