ROTARY CUTTING TOOL

摘要

Provided is a rotary cutting tool that can increase the overall flexural rigidity of blades used therein, even with blades having small thicknesses. A cutter head for woodworking has fitting grooves formed at circumferential four positions on an outer peripheral side of a body. The fitting groove is curved in small measure in an arc shape in a direction opposite to a direction of rotation of the body. The fitting groove is symmetric on both sides of the body. The fitting grooves are each mounted with a blade and a wedge bar. The blade is a long and thin plate having a nearly rectangular shape and elastically deformable. The blade is made of a steel material or a cemented carbide and about 0.5 mm in thickness. The blade is curved in an arc shape that corresponds to the shape of the fitting groove in a direction opposite to a direction of rotation R and then fixated in the curved state. A twist angle representing an angle of inclination of a cutting edge in each blade from a shaft center on an outer peripheral surface of the body is a negative twist angle that changes in a curve on the side of one end surface of the body but is a positive twist angle that changes in a curve on the side of the other end surface of the body.