An object of this disclosure is to provide a cutting insert that is shaped so that a major cutting edge is not damaged easily. In the cutting insert, a major cutting edge, a corner edge, a flat cutting edge and an inner cutting edge are formed on at least an upper surface, a protruding portion protruding outward is formed in a major cutting edge side surface portion of a side surface that corresponds to the major cutting edge, and a first section is formed in which, when viewed from above, the protrusion amount becomes smaller as the protruding portion separates from the corner edge. Furthermore, the cutting insert includes a first clearance angle changing portion in which a clearance angle becomes smaller as a major cutting edge flank portion formed in a major cutting edge side surface portion separates from the corner edge, and a second clearance angle changing portion in which the clearance angle becomes larger as the major cutting edge flank portion separates from the corner edge, wherein the first clearance angle changing portion is preferably positioned closer to the corner edge than the second clearance angle changing portion is, and, of end portions of the first clearance angle changing portion, the value of the clearance angle at a distal end portion from the corner edge is preferably negative.

An insert may include a first surface, a second surface, a ridge line located at an intersection of the first surface and the second surface. The first surface may include a first corner, a first side and a second side. The ridge line may include a corner cutting edge located on the first corner, a first cutting edge located on the first side, and a second cutting edge located on the second side. The first surface may further include a first region located from the first cutting edge toward a midportion of the first surface, a second region located from the second cutting edge toward the midportion of the first surface, and a concave part located on at least one of the first region and the second region.

Disclosed is an indexable face milling cutting insert which comprises an insert body and a cutting body laminated on an upper surface of the insert body, and the insert body comprises multiple positioning side surfaces, an upper plane, and a positioning bottom surface; a projection of an edge of the positioning bottom surface, or an extension line thereof, on a rake face is intersected with a corresponding edge of the rake face, or an extension line thereof, to form a surface deflection angle and multiple flank faces are arranged between the rake face and the multiple positioning side surfaces, so as to avoid damaging the positioning side surfaces when a cutting edge is sharpened, thereby ensuring stability and long-term effect of a positioning reference, and a face cutting milling and a wiper face milling are applicable to a same face milling insert retaining slots.

A compression milling cutter includes a shank and a front cutting portion that terminates at a leading end of the milling cutter. The front cutting portion has a first circumferential row of one or more insert receiving pockets proximate a leading end of the milling cutter, and a second circumferential row of one or more insert receiving pockets, each insert receiving pocket configured to receive a respective indexable cutting insert. The cutting insert mounted in the first circumferential row has a positive axial rake angle, A, and the indexable cutting insert mounted in an insert pocket of the second circumferential row has a negative axial rake angle, B. Because of the different axial rake angles, chips generated during a machining operation flow in opposite directions, thereby creating a compression zone disposed between the first and second circumferential rows. This compression zone replicates the cutting action of a solid end mill, particularly when machining fiber reinforced plastic materials.

A cutting tool has a cutting body with a first insert pocket and an indexable cutting insert removably mounted therein. The first insert pocket has a first seat surface with a plurality of first engagement elements and a first support wall transverse thereto. The cutting insert has upper and lower surfaces and a boundary surface extending therebetween. The lower surface has a plurality of lower engaging elements and the boundary surface has a plurality of alternating first and second peripheral surfaces intersecting the upper surface to form first and second upper cutting edges. In each index position with the lower surface in contact with the first seat surface, the first support wall prevents translation of the cutting insert in a first direction, and the first engagement elements eccentrically contact the lower engaging elements to prevent translation of the cutting insert in a second direction perpendicular to the first direction.

A cutting insert (1) according to an embodiment has a lower surface (2), an upper surface (3), a side surface (4) disposed between the lower surface (2) and the upper surface (3), a pair of corner cutting edges (5) located along an intersection of the upper surface (3) and the side surface (4), and a major cutting edge (6) located between the pair of corner cutting edges (5). The major cutting edge (6) has a downwardly dented curvilinear part (61) and a pair of straight parts (62) respectively extending from the curvilinear part (61) toward the pair of corner cutting edges (5) in a side view. A portion (6p) of the curvilinear part (61) located lowermost is close to one corner cutting edge (5b) in the side view.

A cutting tool has a cutting body with a first insert pocket and an indexable cutting insert removably mounted therein. The first insert pocket has a first seat surface with a plurality of first engagement elements and a first support wall transverse thereto. The cutting insert has upper and lower surfaces and a boundary surface extending therebetween. The lower surface has a plurality of lower engaging elements and the boundary surface has a plurality of alternating first and second peripheral surfaces intersecting the upper surface to form first and second upper cutting edges. In each index position with the lower surface in contact with the first seat surface, the first support wall prevents translation of the cutting insert in a first direction, and the first engagement elements eccentrically contact the lower engaging elements to prevent translation of the cutting insert in a second direction perpendicular to the first direction.

A cutting edge has a corner cutting edge, a flat drag, and a main cutting edge. The rake surface has a first rake surface portion, a second rake surface portion, and a third rake surface portion. The first rake surface portion has a first inclined surface inclined at a first angle. The second rake surface portion has a second inclined surface inclined at a second angle greater than the first angle. The first end portion and the second end portion are higher than the reference surface in a direction perpendicular to the reference surface, and the main cutting edge extends so as to intersect the reference surface when viewed in a direction parallel to the reference surface. A first step portion rising from the third rake surface portion and continuous with the first rake surface portion is provided on the rake surface.

A compression milling cutter includes a shank and a front cutting portion that terminates at a leading end of the milling cutter. The front cutting portion has a first circumferential row of one or more insert receiving pockets proximate a leading end of the milling cutter, and a second circumferential row of one or more insert receiving pockets, each insert receiving pocket configured to receive a respective indexable cutting insert. The cutting insert mounted in the first circumferential row has a positive axial rake angle, A, and the indexable cutting insert mounted in an insert pocket of the second circumferential row has a negative axial rake angle, B. Because of the different axial rake angles, chips generated during a machining operation flow in opposite directions, thereby creating a compression zone disposed between the first and second circumferential rows. This compression zone replicates the cutting action of a solid end mill, particularly when machining fiber reinforced plastic materials.

The cutting edge has: a corner cutting edge; a flat cutting edge continuous to a first end portion of the corner cutting edge; and a main cutting edge continuous to a second end portion of the corner cutting edge opposite to the first end portion of the corner cutting edge. The rake face has: a first rising surface portion; and a first rake face portion continuous to the first rising surface portion and located opposite to the corner cutting edge when viewed from the first rising surface portion. When viewed in a direction perpendicular to the reference surface, the first boundary includes a first line segment extending, from one of the flat cutting edge and the corner cutting edge, in a direction crossing a straight line extending along the main cutting edge.