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.

In the case of a tool holder having a receptacle for a cutting insert, in particular a tangential cutting insert having eight lips, having a lateral bearing surface, a rear bearing surface and a bottom surface, the bottom surface is quadrangular in plan view and has a raised supporting region which has two supporting surfaces, positioned obliquely with respect to one another, for the cutting insert.

In a cutting tool having an indexable cutting insert with three cutting portions, the cutting insert is removably securable to an insert holder by means of a fastener. The cutting insert has two opposing end surfaces with a peripheral side surface extending therebetween. At least one end surface has a central boss protruding therefrom with a raised support surface, and the peripheral side surface has three abutment recesses. In an end view of the cutting insert, each of the three abutment recesses is visible and located inside a first imaginary circle circumscribing the visible central boss. A holding portion of the insert holder has a seating surface with at least one protuberance protruding therefrom. The support surface is in clamping contact with the seating surface, and exactly two of the three abutment recesses are engaged with the at least one protuberance.

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 tool assembly includes a cutting tool and an indexable cutting insert having an insert index axis. The cutting insert includes parallel insert first and second sides connected by an insert peripheral surface that extends peripherally around the cutting insert. At least one clamping hole opens out to one or both of the insert first and second sides, and at least a portion of the clamping hole is in a clamping region of the cutting insert. The insert peripheral surface includes cutting edges that are spaced-apart and extend from the insert first side to the insert second side. Along a width direction, which is perpendicular to the insert first and second sides, each of the cutting edges is wider than the cutting insert, at least at the cutting region of the cutting insert.

A cutting tool having a tool holder, cutting insert and clamping member. The tool holder includes an elongated supporting surface extending in a rearward-to-forward direction. The cutting insert has a central portion and three cutting portions, the central portion having two opposing side surfaces and three spaced apart locating surfaces defining a first imaginary triangle. The cutting insert is indexable about a central axis intersecting the two side surfaces. Each locating surface intersects two of three bisector planes containing the central axis and bisecting respective corners of the first imaginary triangle, and the cutting edge of each cutting portion is located entirely outside of the first imaginary triangle. In each index position the clamping member is located entirely rearward of a first vertical plane containing the central axis and perpendicular to the rearward-to-forward direction, and one of the locating surfaces is in clamping contact with the supporting surface.

An indexable cutting insert comprises a flank face having a generally parallelogram shape and a plurality of side faces. The flank face is bounded by a plurality of edges. Each edge joins the flank face with one of the side faces. The plurality of edges comprises a first cutting edge and a second cutting edge. The first cutting edge has a shape corresponding to a portion of a first bent curve and the second cutting edge has a shape corresponding to a portion of a second bent curve. The second bent curve is obtainable by a translation of the first bent curve along a width direction of the cutting insert. The cutting insert has a two-fold rotational symmetry with respect to an axis of symmetry that is perpendicular to the width direction, a longitudinal direction of the cutting insert being perpendicular to the width direction and the axis of symmetry.

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 two-way indexable V-shaped cutting insert having first and second rake surfaces located in a front insert surface thereof. First and second relief surfaces respectively connect the first and second rake surfaces to first and second converging insert abutment surfaces, respectively. A first cutting edge is located at an intersection of the first rake surface and the first relief surface. A second cutting edge is located at an intersection of the second rake surface and the second relief surface. A first relief angle is formed between the first relief surface and the first converging insert abutment surface. A second relief angle is formed between the second relief surface and the second converging insert abutment surface. The first and second relief angles are obtuse. In a cutting tool, the two-way indexable V-shaped cutting insert is releasably secured in a tool holder by means of a fastening member.

A cutting insert includes opposing insert first and second side surfaces. The insert first side surface includes a first mounting arrangement. The first mounting arrangement includes a) at least one first side abutment surface facing away from the insert second side surface, b) a first stopper abutment surface oriented transversely to the at least one first side abutment surface and c) two opposite-facing first wedge abutment surfaces oriented transversely to the at least one first side abutment surface and converging forwardly. An insert holder has a corresponding pocket mounting arrangement for engagement with the first mounting arrangement.