The end cutting edges formed on the front end face of the tool body includes a first end cutting edge that is connected to the front end of the thread cutting edge, and a second end cutting edge that is connected to the first end cutting edge on the side closer to the axis, and is angled more toward the rear end than the first end cutting edge. The angle formed by an imaginary plane perpendicular to the axis and the first end cutting edge is set to 6° or less. The angle formed by the second end cutting edges and the imaginary plane perpendicular to the axis and is set to be greater than the angle formed by the first end cutting edges and the imaginary plane perpendicular to the axis.

The end cutting edges formed on the front end face of the tool body includes a first end cutting edge that is connected to the front end of the thread cutting edge, and a second end cutting edge that is connected to the first end cutting edge on the side closer to the axis, and is angled more toward the rear end than the first end cutting edge. The angle formed by an imaginary plane perpendicular to the axis and the first end cutting edge is set to 6 or less. The angle formed by the second end cutting edges and the imaginary plane perpendicular to the axis and is set to be greater than the angle formed by the first end cutting edges and the imaginary plane perpendicular to the axis.