In a cutting tool having an indexable lay-down cutting insert with a central body portion and three circumferentially spaced apart cutting portions, the cutting insert is removably secured to an elongated holding portion of an insert holder. Each cutting portion has a cutting edge with first and second cutting end points, the cutting edge formed at the intersection of an upward facing rake surface and a radially outward facing relief surface. In a top view of the cutting insert, parallel imaginary first and second vertical planes containing the first and second cutting end points, intersect the central body portion at first and second body side points, which are located first and second cutting distances from the first and second cutting end points, respectively. Each of the first and second cutting distances is greater than twenty-five percent of the first radius of an imaginary first circle circumscribing the cutting insert.

A cutting insert for a rotary cutting tool has a second surface that includes a second seating surface having a shape of a flat surface. The first cutting edge has a first main cutting edge portion and a first sub cutting edge portion. The second cutting edge has a second main cutting edge portion and a second sub cutting edge portion. When viewed in a direction from the first surface toward the second surface, at least a portion of the second sub cutting edge portion is located outside the first main cutting edge portion, and at least a portion of the first sub cutting edge portion is located outside the second main cutting edge portion. When viewed in the direction from the first surface toward the second surface, each of the first sub cutting edge portion and the second sub cutting edge portion has a shape of a curved line.

In a cutting tool having an indexable lay-down cutting insert with a central body portion and three circumferentially spaced apart cutting portions, the cutting insert is removably secured to an elongated holding portion of an insert holder. Each cutting portion has a cutting edge with first and second cutting end points, the cutting edge formed at the intersection of an upward facing rake surface and a radially outward facing relief surface. In a top view of the cutting insert, parallel imaginary first and second vertical planes containing the first and second cutting end points, intersect the central body portion at first and second body side points, which are located first and second cutting distances from the first and second cutting end points, respectively. Each of the first and second cutting distances is greater than twenty-five percent of the first radius of an imaginary first circle circumscribing the cutting insert.

The present disclosure's technical object is to provide a high feed cutting insert capable of providing a sufficient entering angle while ensuring rigidity of a cutting tool's bottom part. For this, the high feed cutting insert of the present disclosure comprises a short cutting edge provided on a boundary portion between a main surface and a short side surface, a long cutting edge provided on a boundary portion between the main surface and a long side surface, two ascending corner cutting edges connecting the short cutting edge and the long cutting edge, and placed on one diagonal position, and two descending corner cutting edges placed on the other diagonal position and having the height lower than that of the ascending corner cutting edges, wherein the short cutting edge and the long cutting edge, when viewed towards the main surface, form an obtuse angle while the ascending corner cutting edges are interposed therebetween and form an acute angle while the descending corner cutting edges are interposed therebetween.

A cutting insert has a seating surface, an outer peripheral surface, a top surface, and an attachment hole. The cutting edge includes a curved cutting corner edge portion, a first cutting edge portion, and a second cutting edge portion. The top surface includes a first rake face contiguous to the first cutting edge portion, a second rake face contiguous to the second cutting edge portion, and a third rake face contiguous to the cutting corner edge portion and also contiguous to the first and second rake faces. The third rake face has a first region contiguous to the first rake face and a second region contiguous to the second rake face. The first rake face and the first region each have a rake angle which is a positive angle. The second rake face and the second region each have a rake angle which is a negative angle.

In an end view, a cutting insert 10 comprises a first connecting part 30A which is inclined such that the first connecting part 30A travels in a first direction as it heads away from a second peripheral side surface part 18 and approaches a fourth peripheral side surface part 22, and also comprises a second connecting part 30B which is connected to a center point serving as an end of the first connecting part 30A and which is inclined such that the second connecting part 30B travels in a third direction as it heads away from the second peripheral side surface part 18 and approaches the fourth peripheral side surface part 22. A cutting edge 24 comprises: a first cutting edge part 24A which is formed on the first connecting part 30A so as to be distant, by a first distance L1, from a virtual plane PR1 including a center point C1; a second cutting edge part 24B which has, in a side view, a concave circular-arc shape having a second curvature radius smaller than a first curvature radius and which is formed on the second connecting part 30B so as to be distant, by a second distance L2 greater than the first distance L1, from the virtual plane PR1; and a third cutting edge part 24C connecting the first cutting edge part 24A and the second cutting edge part 24B.

A cutting tool may have a columnar shape extended along a rotation axis from a first end toward a second end, and may include a holder, a first insert and a second insert. The holder may include a first pocket, a second pocket, a first flute and a second flute. The second pocket may be located closer to the second end than the first pocket. The first flute may be extended along the first pocket. The second flute may be extended along the second pocket. A first length from the rotation axis to the first flute may be smaller than a second length from the rotation axis to the second flute. An opening width of the first flute may be smaller than an opening width of the second flute.

A cutting insert has a seating surface, an outer peripheral surface, a top surface, and an attachment hole. The cutting edge includes a curved cutting corner edge portion, a first cutting edge portion, and a second cutting edge portion. The top surface includes a first rake face contiguous to the first cutting edge portion, a second rake face contiguous to the second cutting edge portion, and a third rake face contiguous to the cutting corner edge portion and also contiguous to the first and second rake faces. The third rake face has a first region contiguous to the first rake face and a second region contiguous to the second rake face. The first rake face and the first region each have a rake angle which is a positive angle. The second rake face and the second region each have a rake angle which is a negative angle.

Provided is a milling/cutting tool including: a tool main unit that is rotated about an axis; and a plurality of tips that are disposed at one end surface of the tool main unit with spacings therebetween in a circumferential direction about the axis of the tool main unit, wherein the individual tips are disposed so that turning rake surfaces thereof are inclined in the axial directions.

The present disclosure's technical object is to provide a high feed cutting insert capable of providing a sufficient entering angle while ensuring rigidity of a cutting tool's bottom part. For this, the high feed cutting insert of the present disclosure comprises a short cutting edge provided on a boundary portion between a main surface and a short side surface, a long cutting edge provided on a boundary portion between the main surface and a long side surface, two ascending corner cutting edges connecting the short cutting edge and the long cutting edge, and placed on one diagonal position, and two descending corner cutting edges placed on the other diagonal position and having the height lower than that of the ascending corner cutting edges, wherein the short cutting edge and the long cutting edge, when viewed towards the main surface, form an obtuse angle while the ascending corner cutting edges are interposed therebetween and form an acute angle while the descending corner cutting edges are interposed therebetween.