Subject: self-drilling screw. Constitution: three parts (the screw shank (fig.1), the threaded shell (fig.2) and the cutting tool (fig 3.4). The screw shank has a special guide (fig.1.1) allowing the screw shank to move in the clock-wise and anti-clockwise manner inside the threaded shell with the assistance of the specially-configurated interior of the threaded shell (a spiral channel) adjoined by the guide of the base of the screw shank with the purpose of allowing the up-and-down motion of this last. The difference between the length of the cross section of the screw shank and the greater cross section of the inside of the threaded shell enables this last to completely penetrate -after previous insertion of the screw shank- into the wall with the assistance of the oppositely-directed pressure of the movement of the driller; a minimal void surface is left between the body of the screw shank and the interior of the threaded shell so that a unified body may be screwed inside the wall. Embodiment: in industrial constructions and buildings; fixing of heavy materials etc.
