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.

An indexable cutting insert has opposing first and second polygonal end surfaces (2, 3) connected by a peripheral side surface (4). Sets of cutting edges (5) are formed at the intersection of each end surface with the peripheral side surface. Each set of cutting edges includes a corner cutting edge (6), first and second cutting edges (7), (8) on opposite sides of the corner cutting edge (6) and a wiper edge (9) formed between the second cutting edge (8) and the corner cutting edge (6). The peripheral side surface (14) includes a wiper-edge side surface (14) having constant width as it extends between the first and second end surfaces (2, 3). A boundary of the wiper-edge side surface (14) with a second side surface below the second cutting edge (8) is inclined with respect to a direction perpendicular to the first end surface.

In an embodiment, a cutting insert includes an upper surface, a one or more side surfaces, and a cutting edge. The upper surface includes a first corner portion, and a first side that is adjacent to the first corner portion. The one or more side surfaces are adjacent to the upper surface. The cutting edge is disposed on at least a portion of a section where the upper surface and the side surfaces intersect. When viewed from directly above, the cutting edge includes first, second, third and fourth cutting edges. The first cutting edge is disposed at the first corner portion and has a convex curved shape. The second cutting edge is next to the first cutting edge, and has a linear shape. The third cutting edge is next to the second cutting edge, and has a convex curved shape. The fourth cutting edge is next to the third cutting edge on the first side.

The invention is directed to a drill system that better uses the power curve of modern machine tools. The drill system uses IC inserts to perform the major hole diameter cutting, and a central drilling system that cuts the remaining minor diameter portion of the hole, and is configured to see less cutting surface footage, due to its position from the rotating center of the tool. A connection between the drill head and a holder body secures the drill head in a manner to effectively absorb lateral drilling forces. The drill system allows for a large diameter deep hole that remains straight throughout to be drilled at higher speed and lighter feed rates thus offering a more productive tool that takes advantage of the power curves and lower thrust capabilities of modern machine tools.

A method and a device for machining a workpiece rotating about a rotational axis. The machining point moves along the cutting edge of a cutting edge plane and the surface to be machined in a rolling movement on an advancement plane not intersected by the rotational axis. A pivot drive implements a large enough pivot angle so that a first workpiece surface is machined by a machining point moving along the first cutting edge in a first machining step. In a second machining step, a second workpiece surface is machined, wherein the machining point moves along the second cutting edge and the second workpiece surface. The cutting edge has a curvature radius smaller than the distance from the pivot axis of the holder to the cutting edge. The holder can additionally be displaced on the advancement plane with a movement component in a direction transverse to the rotational axis.

The invention is directed to a drill system that better uses the power curve of modern machine tools. The drill system uses IC inserts to perform the major hole diameter cutting, and a central drilling system that cuts the remaining minor diameter portion of the hole, and is configured to see less cutting surface footage, due to its position from the rotating center of the tool. A connection between the drill head and a holder body secures the drill head in a manner to effectively absorb lateral drilling forces. The drill system allows for a large diameter deep hole that remains straight throughout to be drilled at higher speed and lighter feed rates thus offering a more productive tool that takes advantage of the power curves and lower thrust capabilities of modern machine tools.

An indexable cutting insert has opposing first and second polygonal end surfaces (2, 3) connected by a peripheral side surface (4). Sets of cutting edges (5) are formed at the intersection of each end surface with the peripheral side surface. Each set of cutting edges includes a corner cutting edge (6), first and second cutting edges (7), (8) on opposite sides of the corner cutting edge (6) and a wiper edge (9) formed between the second cutting edge (8) and the corner cutting edge (6). The peripheral side surface (14) includes a wiper-edge side surface (14) having constant width as it extends between the first and second end surfaces (2, 3). A boundary of the wiper-edge side surface (14) with a second side surface below the second cutting edge (8) is inclined with respect to a direction perpendicular to the first end surface.