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 in front of the main body section. The cutting section includes a front cutting edge disposed along a ridge line of the cutting section at an intersection between a top surface and a first side surface; and a lateral cutting edge disposed along the ridge line at an intersection between the top surface and a second side surface and inclined with ascending as getting away from the front cutting edge. The lateral cutting edge each includes a first region and a second region located to a rear of the first region; and an angle of inclination of the second region with respect to the bottom surface is larger than an angle of inclination of the first region with respect to the bottom surface.

A tool holder includes a tool shank and a tool head connected to the tool shank. The tool head has a rear surface. An insert seat or a blade pocket is partially formed on both the tool head and the tool shank, and extends rearwardly of the tool head's rear surface. Adjacent to at least a portion of a shank side surface there is a reinforcement portion connecting the shank side surface and the tool head.

A cutting tool includes a two-way indexable cutting insert retained in a tool holder by a clamping member. The cutting insert has a tetrahedral basic shape and includes two cutting edges at opposite ends of thereof. The insert holder includes a forwardly located mounting portion that includes three spaced apart mounting jaws which together define an insert receiving pocket having a pocket opening. The clamping member is attached to the insert holder body so that a clamping portion of the clamping member protrudes into the pocket opening. When the cutting insert is releasably attached to the insert holder in a fastened position of a cutting tool, the cutting insert is located in the insert receiving pocket and clampingly engaged therein by the clamping portion.

A cutting insert includes an insert body, a rake face on an upper surface of an end portion of the insert body, a cutting edge on a ridge between the rake face and an end surface of the insert body, side cutting edges on ridges between the rake face and side surfaces of the insert body, each connected to both end portions of the cutting edge, and a breaker convex portion on the rake face. The breaker convex portion includes two breaker island portions extending toward the side cutting edge as extending closer to the front cutting edge. Each breaker island portion includes from the front cutting edge side a first raised portion, a descending portion which becomes lower from a top portion of the first raised portion, and a second raised portion which becomes higher, from the descending portion, than the top portion of the first raised portion.

A swiss insert includes a chip former arrangement. The chip former arrangement includes a ridge separated on each side from a cutting edge's sub-edge by a chip surface. In a side view, each sub-edge extends in a straight line.

A cutting insert (1) includes a top surface (6), a side surface, a rake face (10) on the top surface (6), a front flank face (11) and a lateral flank face (12), a cutting edge (9) including a front cutting edge (13), and a lateral cutting edge (14), a breaker groove (15) adjacent to the front cutting edge (13) and the lateral cutting edge (14), and a rake face end (20). The breaker groove (15) includes a descending surface (16) and an ascending surface (17). The ascending surface (17) includes a front wall surface (21) and a lateral wall surface (22) on the side of the front cutting edge (13) and the side of the lateral cutting edge (14). An opening angle (1) of the front wall surface (21) is greater than an opening angle (2) of the lateral wall surface (22) in the top surface (6) view.

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.

A cutting tool comprising a holder (12) having a slot-shaped, arcuate receptacle (16), with respectively a lower and an upper bearing surface (36, 38) attached to rigid clamping jaws (18, 20) of the holder (12), for the reception (16) of a cutting insert, (14) and a cutting insert (14) having an arcuate shank (22) with lower and upper locating face (32, 34), which cutting insert is arranged exchangeably in the receptacle (16), and having a cutting head (24) with cutting edge (26), which cutting head is disposed on a workpiece-side end (44) of the shank (22), wherein the arcuate receptacle (16) and the arcuate shank (22), measured respectively on the lower bearing surface (36) of the receptacle (16) and the lower locating face (32) of the cutting insert (14), extend respectively over at least 90, wherein the receptacle (16) extends over a larger angular range than the shank (22) of the cutting insert (14), and wherein the shank (22) is held in the receptacle (16) such that the holder-side end (28) of the shank (22) is distanced from the holder-side end (30) of the receptacle (16).

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.