The invention discloses a fastener. Mainly, a plurality of first threads and a plurality of second threads are arranged on a rod body. Meanwhile, an outward-protruding backstop rib is arranged at the position, among any two first threads and any two second threads annularly arranged on the corresponding first threads, of the periphery of the rod body. The backstop ribs extend from the periphery of the rod body and are connected to first upper thread faces of the first threads and second upper thread faces of the second threads annularly arranged on the first threads. Meanwhile, the inclination angle of the backstop ribs and the periphery of the rod body are arranged in a conical shape with 5-10 degrees. Thus, grooves in the second threads are used for assisting in cutting objects and containing cuttings, the first threads are used for reinforcing the drilling and locking stress of the second threads, and then the backstop ribs are used in a matched manner in good time to increase the torsion resisting force and tensile resisting force in the drilling and locking process, so that the function of preventing loosening and retreating after drilling and locking is achieved, and the locking fastening force and the locating effect are greatly improved.