An object of the present invention is to provide a cutting tool capable of cutting head detachably limiting the torque due to the excessive fastening force and cutting force between the cutting head and the holder, and to minimize the tension through the stopper (stopper). The possible removal of the cutting tool cutting head in accordance with one embodiment of the present invention includes a holder 200 coupled to the cutting head 100 and the cutting head 100. The cutting head 100 includes a projecting portion on one axial side of the cutting head 100, one end shaft protruding in a direction from the number of the outer circumferential surface and a threaded projection (110) (111) is formed, the cutting head 100 of the ( 110) to be at least one that is formed so as to surround the circumferential direction comprises a first helical surface 130 and the first at least one first stopper 120 formed in the step portion that is discontinuous in height of the helical surface 130. Holder 200 has a screw hole 210 for axial screwed extend inwardly and the female thread 211 is formed on the inner circumferential surface and a projecting portion 110 of the cutting head 100 in the direction from one end of the holder 200, and , holder 200, one end shaft at least one is formed so as to surround the threaded hole 210 on the plane direction in the circumferential direction of the second spiral surface 230, the second spiral step portion that the height of the surface 230 discontinuities comprises at least one second stopper 220 is formed on. A first helical surface 130 and the second spiral surface 230 has the same lead angle. Coupling when the first screw surface 130 and the second spiral surface 230 of the protrusion 110 and a screw hole 210 form a surface contact. Claim that the screw engagement of the protrusions 110 and the screw hole 210 is completed as the first stopper 120 and second stopper 220 are in contact.