Abstract: A concrete screw includes a rod body which has a top end forming a head for tightening operation and a bottom end forming an engaging section. A first thread is formed on the rod body and extends, at a helix angle between 16 and 23 degrees, from the head toward the engaging section. The first thread has a top-side flank that defines a first thread flank angle ranging from 90 to 120 degrees with respect to the rod body. The first thread has a pitch that ranges from 5 mm to 20 mm. Three cutting notches are formed in and distributed along the first thread and are close to the engaging section. The cutting notches have a depth substantially corresponding to a distance from an apex of the first thread to the rod body. The rod body may selectively form a second thread extending between the head and the engaging section.