The  HR 420-800   is our largest model, it has been designed and built specifically for the execution of jobs that require drilling large diameters and great depths. 
This drilling machine can be equipped with different rotaries with different torque values ​​based on work needs. Furthermore, the rotary can be equipped with the MCS (MAIT Casing System) or torque multiplier, which exerts a maximum nominal torque of 800 KNm in the insertion and extraction of form tubes up to a maximum diameter of 3,000 mm. The HR 420-800 is not limited to the conventional rod drilling system, but can work with column vice, continuous auger (CFA), rod diaphragms and piles driven with hydraulic hammers. The HR 420-800 is also available with a push-pull winch (THD), which allows for a greater stroke of the rotary along the tower, thanks to which longer sections of form tubes can be used.