A cutting insert in the present disclosure includes an upper surface, a lower surface, a side surface, and an edge. The upper surface includes a first corner part and a second corner part. The edge is located in a region which is located between the first corner part and the second corner part. The edge includes a first edge located at a side of the first corner part, a second edge located at a side of the second corner part, and a third edge located between the first edge and the second edge. The edge has a curvilinear shape being recessed toward the lower surface in a side view. Each of a radius of curvature R1 of the first edge and a radius of curvature R2 of the second edge is smaller than a radius of curvature R3 of the third edge in a side view.

A cutting insert includes a leading cutting edge having a rake angle in the range of 20 to 35 in a central region in a width direction; and a rake face having a breaker groove formed in the central region in the width direction and land portions formed in both end regions in the width direction. The land portions have a rake angle smaller than the rake angle in the central region in the width direction. The breaker groove includes opposing side faces separated from each other by a distance that decreases with increasing distance from the leading cutting edge and four shoulder portions of the same height that are formed on the opposing side faces at positions above the land portions, two of the shoulder portions being closer to the leading cutting edge and to outer sides in the width direction than the other two shoulder portions are.

A cutting insert of one aspect includes a top surface including a corner portion and a pair of side portions each adjacent to the corner portion, a bottom surface, a side surface located between the top surface and the bottom surface, and a corner cutting edge disposed at the corner portion. In such a cutting insert, the top surface includes a first rake surface located along the corner cutting edge, a raised portion located farther on the inner side than the first rake surface, and a second rake surface located between the corner cutting edge and the raised portion. Moreover, a rake angle at a first region of the second rake surface corresponding to a center of the corner cutting edge is greater than a rake angle at a second region of the second rake surface located beside the first region.

Chip discharge during high-feed machining and low-feed machining particularly in a high-depth-of-cut state or the like is improved so as to provide adaptability to a wide range of cutting conditions during low depth and high depth cutting and during low-feed and high-feed machining and allow so-called freedom of feed during cutting to be improved. A cutting insert includes a cutting edge body and a substrate to which the cutting edge body is joined. The cutting edge body has a prismatic shape having a longitudinal direction and a lateral direction perpendicular to the longitudinal direction and includes a cutting edge formed on an intersecting edge between a peripheral side surface and an upper surface of the cutting edge body having the prismatic shape and a recessed part formed at a position on the upper surface of the cutting edge body which is more distant from the intersecting edge than from the cutting edge. The substrate has a projected part upwardly projecting from the upper surface of the cutting edge body.

A cutting tool according to this invention includes a cutting edge configured to cut a workpiece; a rake surface configured to come in contact with a chip, which appears when the workpiece is cut by the cutting edge; and a relieved surface configured to come in contact with a to-be-cut surface of the workpiece. A plurality of first grooves are formed in the cutting edge side of the rake surface. A plurality of second grooves are formed in the cutting edge side of the relieved surface.

A cutting insert according to an embodiment of the present invention has a body section and a cutting section located closer to a front end side than the body section. The cutting section has an end cutting edge located along an intersection of an upper surface and a side surface, a recess located from the end cutting edge toward the body section, and a pair of protrusions opposed to each other with the recess interposed therebetween. The pair of protrusions has a first protrusion and a second protrusion located on the first protrusion. The first protrusion has a first inclined surface that is inclined upward and approaches another one of the pair of protrusions as going from the front end side toward the rear end side. A periphery of the second protrusion which is close to the front end side has a convex curvilinear shape in a top view.

The invention relates to an interchangeable cutting insert (10) having a shank (12), which transitions into a cutting head (14), which has a chipping surface (32), which, when viewed from above, is a segment of a circle with a height greater than the radius of the chipping surface (32), wherein the chord of the segment of a circle constitutes the transition to the shank (12), wherein a cutting edge (30) is formed on the outer edge of the chipping surface and multiple chip-breaking structures (36, 38) are provided on the chipping surface (32), the chip-breaking structures having depressions (36) in the chipping surface (32), between which projections (38) are arranged, which protrude beyond the chipping surface (32).

A cutting insert has parallel first upper and lower faces, parallel second upper and lower faces, first and second side faces, first and second cutting portions, and first and second mounting grooves. The second upper and lower faces are perpendicular to the first upper and lower faces, respectively. The first and second side faces are located at respective ends of the cutting insert. The first cutting portion has a major cutting edge at an edge between the first upper face and the first side face, while the second cutting portion has a major cutting edge at an edge between the second upper face and the second side face. The first mounting groove curvedly or linearly extends from the first cutting portion oppositely to the second cutting portion, while the second mounting groove curvedly or linearly extends from the second cutting portion oppositely to the first cutting portion.

A cutting insert of one aspect includes a main body section and a cutting section located at least at the front end side of the main body section, wherein the cutting section includes a top surface and a front cutting edge disposed along a ridge line at an intersection between the top surface and a front side surface, the front cutting edge includes a first section, a second section, and a third section, and a portion of the second section is located above the first section and the third section. The front side surface includes a first region located below the first section, a second region located below the second site, and a third regions located below the third site, wherein an angle of inclination of the second region is greater than angles of inclination of the first region and the third region.

A non-indexable, one-sided cutting insert includes opposite insert side surfaces which define an insert width therebetween, opposite insert front and rear surfaces which extend between the insert side surfaces and define an insert depth therebetween and opposite insert top and bottom surfaces which extend between the insert side surfaces and the insert front and rear surfaces. The insert top and bottom surfaces define an insert height therebetween. The insert further includes a main cutting edge formed at an intersection between the insert top and front surfaces. A maximum value of the insert width is smaller than minimum value of the insert height, and a minimum value of the insert depth. The insert includes a deep opening which opens out only to the insert bottom surface and defines an opening depth. A depth ratio defined between the opening depth and the insert height is greater than 0.3.