Abstract: A drill head for a drilling device for making drill holes in insufficiently stable foundation by displacement of soil material has a base plate, with which the drill pipe end is detachably connected and is closable, on which base plate at least one drill head plate, oriented substantially perpendicular thereto, is placeable. Insertable in the lateral flanks is at least one curved plate, which is provided with first holding means, which are held in second holding means, which are attached on the lateral flanks of the drill head plate. The curved plate is designed in a way and is insertable in the flanks of the drill head plate such that its surfaces are effective as screw faces during the drilling process. The efficiency of the drilling can thereby be improved.