A cutting insert (10) for a tool (100) for machining a workpiece. The cutting insert (10) is a four-bladed cutting insert which is in the form substantially of a rhomboid. The cutting insert (10) has two identical, oppositely arranged base sides (14a, 14b) and four identical main sides (16a-16d) which extend between the two base sides (14a, 14b). Each of the four main sides (16a-16d) comprises a rectilinear main cutting edge (12a-12d) and a rectilinear secondary cutting edge (26a-26d) which is arranged transversely thereto. The main and secondary cutting edges (12a-12d) and (26a-26d) of each main side (16a-16d) lie in each case in a common cutting plane which is aligned parallel to a contact surface (28a-28d) which is also provided on the main sides (16a-16d).

What is presented is a cutting insert including a polygonal plate-shaped insert main body that includes: two polygonal surfaces; a side surface; and a cutting edge, the insert main body has a mounting hole that is centered on an insert center line passing through centers of the two polygonal surfaces, the cutting edge includes a major cutting edge extending from a first end of a corner edge located at a corner of the polygonal surface, and, in the opening of the mounting hole, a plurality of protrusions protruding with respect to a boss surface around an opening of the mounting hole are formed at intervals in a peripheral direction in an inner periphery side region of the major cutting edge.

A cutting insert may include a first surface having a polygonal shape, a second surface, a third surface and a cutting edge. The first surface may include a first corner, a first side, a first inclined surface located along the first side, and a second inclined surface located along the second side. In a plan view of the first surface, a width of the first inclined surface in a direction orthogonal to the first side may become larger as approaching the second side. A width of the second inclined surface in a direction orthogonal to the second side may become larger as approaching the first side.

An insert configured to be assembled to a tool for cutting a workpiece, includes: an upper surface including first to fourth upper corner portions formed in respective quadrants divided by a first imaginary vertical axis and a first imaginary horizontal axis that are perpendicular to each other; and a lower surface formed below the upper surface in a height direction and including first to fourth lower corner portions formed in respective quadrants divided by a second imaginary vertical axis and a second imaginary horizontal axis that are perpendicular to each other. A lower ridge portion protruding downward in the height direction is formed on the lower surface, and extends across the second and fourth lower corner portions, which are symmetrical with respect to a center of the lower surface

An insert may include a first surface, a second surface, a ridge line located at an intersection of the first surface and the second surface. The first surface may include a first corner, a first side and a second side. The ridge line may include a corner cutting edge located on the first corner, a first cutting edge located on the first side, and a second cutting edge located on the second side. The first surface may further include a first region located from the first cutting edge toward a midportion of the first surface, a second region located from the second cutting edge toward the midportion of the first surface, and a concave part located on at least one of the first region and the second region.

A cutting insert may include a first surface having a polygonal shape, a second surface, a third surface and a cutting edge. The first surface may include a first corner, a first side, a first inclined surface located along the first side, and a second inclined surface located along the second side. In a plan view of the first surface, a width of the first inclined surface in a direction orthogonal to the first side may become larger as approaching the second side. A width of the second inclined surface in a direction orthogonal to the second side may become larger as approaching the first side.

An indexable cutting insert has opposing upper and lower end surfaces, and a peripheral surface including three side surfaces circumferentially alternating with three corner surfaces. The three side surfaces define an imaginary triangle and an imaginary hexagon. Each corner surface intersects the upper end surface to form an upper corner peripheral edge having a primary cutting edge. In a top view, each triangle side traverses two upper corner peripheral edges, imaginary lines tangential to the end points of each primary cutting edge are either collinear or form an obtuse angle greater than 175 degrees, each primary cutting edge has a primary length greater than half the hexagon side length, and at least one triangle side traverses each primary cutting edge. The insert is removably secured in a rotary cutting tool such that one of the upper corner peripheral edges contains an axially forwardmost point of the insert's upper peripheral edge.

A cutting insert (10) for a tool (100) for machining a workpiece. The cutting insert (10) is a four-bladed cutting insert which is in the form substantially of a rhomboid. The cutting insert (10) has two identical, oppositely arranged base sides (14a, 14b) and four identical main sides (16a-16d) which extend between the two base sides (14a, 14b). Each of the four main sides (16a-16d) comprises a rectilinear main cutting edge (12a-12d) and a rectilinear secondary cutting edge (26a-26d) which is arranged transversely thereto. The main and secondary cutting edges (12a-12d) and (26a-26d) of each main side (16a-16d) lie in each case in a common cutting plane which is aligned parallel to a contact surface (28a-28d) which is also provided on the main sides (16a-16d).

The invention relates to an apparatus for processing cylinder walls of internal combustion engines (1), including a cutting element (4). The cutting element (4) is arranged on a rotary cutting ring (3). The cutting element (4) has a slit contour (5) with a plurality of cutting edges (6) arranged next to each other in a direction of an axis of rotation of the rotary cutting ring. And, the individual cutting edges (6) face in a direction of rotation of the rotary cutting ring.

An insert configured to be assembled to a tool for cutting a workpiece, includes: an upper surface including first to fourth upper corner portions formed in respective quadrants divided by a first imaginary vertical axis and a first imaginary horizontal axis that are perpendicular to each other; and a lower surface formed below the upper surface in a height direction and including first to fourth lower corner portions formed in respective quadrants divided by a second imaginary vertical axis and a second imaginary horizontal axis that are perpendicular to each other. A lower ridge portion protruding downward in the height direction is formed on the lower surface, and extends across the second and fourth lower corner portions, which are symmetrical with respect to a center of the lower surface.