A cutting insert of an embodiment includes a cutting edge located at an intersecting part of an upper surface and a side surface. The cutting edge includes a corner cutting edge, a major cutting edge, and a flat cutting edge. The upper surface includes a first land surface located along the corner cutting edge, a second land surface located along the major cutting edge, and a third land surface located along the flat cutting edge. A maximum value of a width of the third land surface is smaller than a maximum value of a width of each of the first land surface and the second land surface in a top view.

A turning insert for machining both Inconel and Titanium workpieces. The insert includes a chip forming arrangement including only a single v-shaped groove. The groove includes a specific depth and position to improve machining of both Inconel and Titanium work pieces.

The invention suppresses chipping of a cutting edge of a cutting tool while maintaining sharpness of the cutting edge. [Solution] A coating (20) of a replaceable knife (10) of the cutting tool is formed so that either one of a rake-face coating portion (22) that coats a rake face (14) or a clearance-face coating portion (24) that coats a clearance face (16) becomes thicker than the other. The film thickness of the thicker coating portion (22, 24) is set in a range of 0.5 m to 15.0 m, and a ratio of the film thickness of the thinner coating portion (24, 22) to the film thickness of the thicker coating portion (22, 24) is set in a range of 0.01 to 0.15.

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 tool comprises a tool body having a first end and a second end, and a longitudinal axis extending between the first end and the second end. The first end comprises two or more cutting portions, with each of the cutting portions comprising a cutting edge and a flank surface.

Each cutting edge extends radially outwardly from a centre region of the first end to a perimetral edge of the first end, with the cutting edge being angled relative to the longitudinal axis. Each flank surface extends circumferentially from the cutting edge.

Each of at least two of the two or more flank surfaces comprises an abrasive portion extending over at least a part of the respective flank surface and each abrasive portion comprises a plurality of abrasive features.

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 of the present disclosure includes a first surface, a second surface, and a cutting edge. The first surface includes a corner part, and a first side and a second side each extending from the corner part. The second surface connects to the first surface. The cutting edge is located at a region where the first surface intersects with the second surface. The cutting edge includes a first cutting edge located at the first side, a second cutting edge located at the second side, and a third cutting edge located at the corner part. The first cutting edge and the third cutting edge are provided with a honing. A honing width of a side of the second cutting edge in the third cutting edge decreases as going away from the first cutting edge and then approaching the second cutting edge.

A cutting tool for cutting a rotationally symmetrical surface of a rotating workpiece includes the step of feeding the cutting tool in a direction inclined with respect to a rotational axis of the rotationally symmetrical surface, while holding the cutting tool in contact with the rotationally symmetrical surface. In the step of feeding the cutting tool, the cutting tool has a point that is in contact with the rotationally symmetrical surface and the point shifts as the cutting tool is fed. The cutting tool includes: a rake face; a flank face; and a cutting edge connecting the rake face and the flank face. The cutting edge as seen from above the flank face has a shape including at least one arc, and the arc has a radius of curvature of not less than 100 mm and not more than 500 mm.

A surface coated cutting tool having surfaces including a rake face and a flank face and a cutting edge defined by a boundary portion between the rake face and the flank face includes a substrate and a coating which covers the surfaces of the substrate, the coating having a TiAlN layer having an NaCl type crystal structure, and relation of 0.65<XR0.9, 0.65<XF0.9, 0.4XE0.7, XRXE0.2, and XFXE0.2 being satisfied, with a composition of the TiAlN layer in a cutting edge region located in the cutting edge being expressed as Ti.sub.1-XEAl.sub.XEN, a composition thereof in a rake face region located in the rake face being expressed as Ti.sub.1-XRAl.sub.XRN, and a composition thereof in a flank face region located in the flank face being expressed as Ti.sub.1-XFAl.sub.XFN.

The invention suppresses chipping of a cutting edge of a cutting tool while maintaining sharpness of the cutting edge.

[Solution] A coating (20) of a replaceable knife (10) of the cutting tool is formed so that either one of a rake-face coating portion (22) that coats a rake face (14) or a clearance-face coating portion (24) that coats a clearance face (16) becomes thicker than the other. The film thickness of the thicker coating portion (22, 24) is set in a range of 0.5 m to 15.0 m, and a ratio of the film thickness of the thinner coating portion (24, 22) to the film thickness of the thicker coating portion (22, 24) is set in a range of 0.01 to 0.15.