A coated cutting tool for chip forming machining of metals includes a substrate having a surface coated with a chemical vapour deposition (CVD) coating. The substrate is coated with a coating having a layer of α-Al.sub.2O.sub.3, wherein the α-Al.sub.2O.sub.3 layer exhibits a texture coefficient TC(0 0 12)≥7.2 and wherein the ratio of I(0 0 12)/I(0 1 14)≥0.8. The coating further includes a MTCVD TiCN layer located between the substrate and the α-Al.sub.2O.sub.3 layer. The MTCVD TiCN layer exhibits a pole figure, as measured by EBSD, in a portion of the MTCVD TiCN layer parallel to the outer surface of the coating and less than 1 μm from the outer surface of the MTCVD TiCN, wherein a pole plot based on the data of the pole figure, with a bin size of 0.25° over a tilt angle range of 0°≤β≤45° from the normal of the outer surface of the coating shows a ratio of intensity within β≤15° tilt angle to the intensity within 0°≤β≤45° of ≥45%.

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.

The present disclosure relates to a cutting insert, and a cutting insert according to the present disclosure comprises: an upper surface and a lower surface oriented in opposite directions; a first and a second shorter side surface connecting the upper surface and the lower surface to each other and oriented in opposite directions; a first and a second longer side surfaces connecting the upper surface and the lower surface to each other, connecting the first and the second shorter side surfaces to each other, oriented in opposite directions, and being longer than the first and the second shorter side surfaces; and a through hole extending through the upper surface and the lower surface, wherein when viewed toward the upper surface, the first longer side surface has two side portions, each side portion having an inclined shape with reference to the center portion.

An object of the present invention is to provide a cutting tool that requires the smaller number of parts and can be manufactured at a lower cost. A cutting tool includes: a tool body extending along a central axis and rotatable around the central axis; a cutting insert to be mounted on an insert mounting seat of the tool body; and at least one flow passage provided inside the tool body, the at least one flow passage extending from a back end side toward a front end side of the tool body so as to supply a coolant toward at least a part of the inside of the tool body, a back end side of the at least one flow passage being open at a portion sealed by the tool body and the holding member when the holding member is coupled.

An object of the present invention is to provide a cutting tool that requires the smaller number of parts and can be manufactured at a lower cost. A cutting tool includes: a tool body extending along a central axis and rotatable around the central axis; a cutting insert to be mounted on an insert mounting seat of the tool body; and at least one flow passage provided inside the tool body, the at least one flow passage extending from a back end side toward a front end side of the tool body so as to supply a coolant toward at least a part of the inside of the tool body, a back end side of the at least one flow passage being open at a portion sealed by the tool body and the holding member when the holding member is coupled.

The present disclosure relates to a cutting insert, and a cutting insert according to the present disclosure comprises: an upper surface and a lower surface oriented in opposite directions; a first and a second shorter side surface connecting the upper surface and the lower surface to each other and oriented in opposite directions; a first and a second longer side surfaces connecting the upper surface and the lower surface to each other, connecting the first and the second shorter side surfaces to each other, oriented in opposite directions, and being longer than the first and the second shorter side surfaces; and a through hole extending through the upper surface and the lower surface, wherein when viewed toward the upper surface, the first longer side surface has two side portions, each side portion having an inclined shape with reference to the center portion.

A coated cutting tool for chip forming machining of metals includes a substrate having a surface coated with a chemical vapour deposition (CVD) coating. The substrate is coated with a coating having a layer of -Al.sub.2O.sub.3, wherein the -Al.sub.2O.sub.3 layer exhibits a texture coefficient TC(0 0 12)7.2 and wherein the ratio of I(0 0 12)/I(0 1 14)0.8. The coating further includes a MTCVD TiCN layer located between the substrate and the -Al.sub.2O.sub.3 layer. The MTCVD TiCN layer exhibits a pole figure, as measured by EBSD, in a portion of the MTCVD TiCN layer parallel to the outer surface of the coating and less than 1 m from the outer surface of the MTCVD TiCN, wherein a pole plot based on the data of the pole figure, with a bin size of 0.25 over a tilt angle range of 045 from the normal of the outer surface of the coating shows a ratio of intensity within 15 tilt angle to the intensity within 045 of 45%.

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.

A cutting insert and an indexable insert-type cutting tool includes a cutting edge (6A) formed on each of a pair of side ridge portions of at least one of the side faces, wherein an insert main body (1) is formed in the shape of having front-back inversion symmetry which is 180 rotationally symmetrical with respect to a line of symmetry (N) passing through the center of the side faces; a flank face adjacent to the cutting edge (6A) is formed on the side face in the vicinity of each of the pair of polygonal faces (2); each of the flank faces is formed in the shape of a twisted face; the pair of side ridge portions on which the cutting edge (6A) is formed intersect each other in such a manner that the second corner portion (B) of one side ridge portion protrudes outside the other side ridge portion.

A cutting insert includes an insert body having a polygonal plate shape. Rake faces are formed on polygonal surfaces of the insert body, and flank faces are formed on lateral faces of the insert body arranged around the polygonal surfaces. Main cutting edges are formed on side ridges of the polygonal surfaces at intersecting ridgelines between the rake faces and the flank faces. Each main cutting edge extends between two corners adjacent to each other in a circumferential direction of the polygonal surface among corners of the polygonal surface. When seen from a direction opposing the rake face, one end portion of the main cutting edge that stretches to one corner of the two corners has a convexly curved shape, and the other end portion of the main cutting edge that stretches to the other corner of the two corners has a concavely curved shape.