Abstract: A ball nose end mill includes a tool body and a throwaway insert mountable on the tool body. The throwaway insert includes a bottom face as a mounting face, an upper face on an opposite side from the bottom face, a side face formed between the bottom face and the upper face, and a cutting edge formed along an intersecting ridge between the upper face and the side face in a substantially arc shape such that the rotational trace of the cutting edge when the throwaway insert is attached to the tool body in use substantially forms a partial spherical surface. An undulating portion, which is formed by alternately arranged concave portions and convex portions, is provided on the upper face so as to intersect the cutting edge. At least one of the concave portions is formed as a deep-concave portion which has a greater depth than that of the others.

Abstract: A ball nose end mill includes a tool body and a throwaway insert mountable on the tool body. The throwaway insert includes a bottom face as a mounting face, an upper face on an opposite side from the bottom face, a side face formed between the bottom face and the upper face, and a cutting edge formed along an intersecting ridge between the upper face and the side face in a substantially arc shape such that the rotational trace of the cutting edge when the throwaway insert is attached to the tool body in use substantially forms a partial spherical surface. An undulating portion, which is formed by alternately arranged concave portions and convex portions, is provided on the upper face so as to intersect the cutting edge. At least one of the concave portions is formed as a deep-concave portion which has a greater depth than that of the others.

Abstract: A throwaway insert comprises an insert body formed in a polygonal shape, a cutting face formed by a polygonal face of the insert body, a corner cutting edge which is formed in a curved shape at a corner of the cutting face, a major cutting edge which is formed along a side edge of the cutting face that is connected to a first end of the corner cutting edge, and a concave portion which is formed, in another side edge of the cutting face that is connected to a second end of the corner cutting edge, so as to be adjacent to the second end of the corner cutting edge, and so as to be made concave toward the inside of the cutting face from a tangent of the corner cutting edge drawn at the second end of the corner cutting edge. By using the throwaway insert, cut chips are prevented from being packed in a gap between the throwaway insert and a surface being machined, and the fixing rigidity of the throwaway insert is increased.

Abstract: A throwaway insert enables reduction in cutting force and improves chip separation ability without sacrificing the strength of cutting edge thereof. An upper face of the throwaway insert is provided with an undulating portion, which is formed by alternately arranged concave portions and convex portions, so as to provide a wavy shape to the cutting edge. The undulating portion comprises four concave portions, i.e., a first deep-concave portion, a first shallow-concave portion, a second deep-concave portion, and a second shallow-concave portion. The first deep-concave portion and the second deep-concave portion are located so that effective cutting region of the cutting edge is divided into three portions having lengths substantially equal to each other, and the second deep-concave portion is made deeper than the first deep-concave portion.

Abstract: A throwaway insert comprises an insert body formed in a polygonal shape, a cutting face formed by a polygonal face of the insert body, a corner cutting edge which is formed in a curved shape at a corner of the cutting face, a major cutting edge which is formed along a side edge of the cutting face that is connected to a first end of the corner cutting edge, and a concave portion which is formed, in another side edge of the cutting face that is connected to a second end of the corner cutting edge, so as to be adjacent to the second end of the corner cutting edge, and so as to be made concave toward the inside of the cutting face from a tangent of the corner cutting edge drawn at the second end of the corner cutting edge. By using the throwaway insert, cut chips are prevented from being packed in a gap between the throwaway insert and a surface being machined, and the fixing rigidity of the throwaway insert is increased.

Abstract: A throwaway insert comprises an insert body formed in a polygonal shape, a cutting face formed by a polygonal face of the insert body, a corner cutting edge which is formed in a curved shape at a corner of the cutting face, a major cutting edge which is formed along a side edge of the cutting face that is connected to a first end of the corner cutting edge, and a concave portion which is formed, in another side edge of the cutting face that is connected to a second end of the corner cutting edge, so as to be adjacent to the second end of the corner cutting edge, and so as to be made concave toward the inside of the cutting face from a tangent of the corner cutting edge drawn at the second end of the corner cutting edge. By using the throwaway insert, cut chips are prevented from being packed in a gap between the throwaway insert and a surface being machined, and the fixing rigidity of the throwaway insert is increased.

Abstract: A throwaway insert enables reduction in cutting force and improves chip separation ability without sacrificing the strength of cutting edge thereof. An upper face of the throwaway insert is provided with an undulating portion, which is formed by alternately arranged concave portions and convex portions, so as to provide a wavy shape to the cutting edge. The undulating portion comprises four concave portions, i.e., a first deep-concave portion, a first shallow-concave portion, a second deep-concave portion, and a second shallow-concave portion. The first deep-concave portion and the second deep-concave portion are located so that effective cutting region of the cutting edge is divided into three portions having lengths substantially equal to each other, and the second deep-concave portion is made deeper than the first deep-concave portion.

Abstract: A throwaway insert comprises an insert body formed in a polygonal shape, a cutting face formed by a polygonal face of the insert body, a corner cutting edge which is formed in a curved shape at a corner of the cutting face, a major cutting edge which is formed along a side edge of the cutting face that is connected to a first end of the corner cutting edge, and a concave portion which is formed, in another side edge of the cutting face that is connected to a second end of the corner cutting edge, so as to be adjacent to the second end of the corner cutting edge, and so as to be made concave toward the inside of the cutting face from a tangent of the corner cutting edge drawn at the second end of the corner cutting edge. By using the throwaway insert, cut chips are prevented from being packed in a gap between the throwaway insert and a surface being machined, and the fixing rigidity of the throwaway insert is increased.