Abstract: A drill includes a main body and a high-hard tip attached to a front end of the body. The tip has a width greater than the diameter of the body and has an angular cutting portion. In order to form a hole having a greater distal end in a wall, the tip is attached on the main body in such a way that a cutting point on an axial line of the tip is eccentrically shifted from an axis of the main body. The drill is inserted into a preliminary hole drilled beforehand and cuts a distal end of the preliminary hole to form a hole including an expanded distal end having a greater diameter. Thereby, the expanded distal end hole having a greater distal end can be formed that is capable of increasing the fixity of an anchor far greater.

Abstract: A drill includes a main body and a high-hard tip attached to a front end of the body. The tip has a width greater than the diameter of the body and has an angular cutting portion. In order to form a hole having a greater distal end in a wall, the tip is attached on the main body in such a way that a cutting point on an axial line of the tip is eccentrically shifted from an axis of the main body. The drill is inserted into a preliminary hole drilled beforehand and cuts a distal end of the preliminary hole to form a hole including an expanded distal end having a greater diameter. Thereby, the expanded distal end hole having a greater distal end can be formed that is capable of increasing the fixity of an anchor far greater.