Undercut anchor bolt suitable for hard materials

The utility model relates to a bolt, and particularly discloses an undercut anchor bolt suitable for hard materials. The undercut anchor bolt comprises a main body, one end of the main body is a head part, and the other end of the main body is a drill tip part; the main body comprises a screw rod, the screw rod is provided with screw teeth, and the screw teeth are spirally arranged in the axial direction from the drill tip part; the screw rod comprises a drilling section and a middle section, and the drilling section corresponds to the drill tip part; notches are formed in the threads corresponding to the drilling subsections, and sawteeth are formed between every two adjacent notches; a supporting convex rib is arranged on the middle subsection, the supporting convex rib is located between every two adjacent threads, and the supporting convex ribs and the threads are spirally arranged in the same direction; the height of the supporting convex ribs is smaller than that of the threads. According to the undercu