A cutting insert includes a top surface, a bottom surface and a plurality of peripheral side surfaces. The top and bottom surfaces and the side surfaces are joined to form rounded cutting corners. A plurality of cutting edges are formed at an intersection between the top surface and the plurality of side surfaces. A pair of asymmetric chip formers are proximate opposite rounded cutting corners. A distance between the opposite rounded cutting corners and the asymmetric chip formers varies in such a way that a ratio of a chip thickness and the distance is substantially constant as a function of a depth of cut.

A polygonal indexable cutting insert including a pair of faces, a plurality of peripheral side surfaces, a plurality of rounded corners, a plurality of cutting edges formed with an edge radius, a plurality of triangular-shaped areas proximate the rounded corners; and a plurality of chip breaking scallops positioned along the cutting edges. Each scallop has a bottom surface formed by a rake face and an arcuate back wall having a varying depth. The arcuate back wall of each scallop intersects the arcuate back wall of adjacent scallops at a point located at a distance from each cutting edge for providing a wedge effect that facilitates in dividing and breaking chips.

The invention relates to a cutting tool for machining, in particular for a peeling-like machining process, comprising a chip-forming depression which runs along the cutting edge and in which elevated chip-forming elements are formed. According to the invention, the elevated chip-forming elements have an elongated contour with a length which is greater than the width, in plan view, such that the chip-forming elements have a rising flank and a falling flank. The rising flank, which is longer by comparison, is defined by a rising angle () of 3 to 20, preferably 5 to 10, and a falling angle () of 25 to 45, preferably 27 to 35, and the transition between the rising flank and the falling flank is rounded, the radius (R) of said rounded section ranging between 0.05 mm and 1 mm, preferably between 0.25 mm and 0.4 mm.

A cutting insert has a top surface, a bottom surface, and an outer peripheral surface. A ridgeline between the top surface and the outer peripheral surface includes a first cutting edge. A protrusion is provided on the top surface. In a first cross section, a distance between the first cutting edge and the protrusion in a direction perpendicular to the bottom surface is defined as a first distance. In a second cross section, a distance between the first cutting edge and the protrusion in a direction perpendicular to the bottom surface is defined as a third distance. The third distance is longer than the first distance. A ratio of a height of the protrusion to a width of the protrusion in the second cross section is smaller than a ratio of a height of the protrusion to a width of the protrusion in the first cross section.

A cutting insert may include an upper surface, a lateral surface, and a cutting edge including a boundary between the upper surface and the lateral surface. The upper surface may include a first rising face that extends upward and a second rising face that is connected to an upper side of the first rising face and extends upward. The first rising face may include a first region that extends along a corner portion and a second region that extends along a side portion. The second rising face may include a third region connected to the first region and a fourth region connected to the second region. An entirety of a boundary between the first region and the third region may be positioned above the cutting edge. A boundary between the second region and the fourth region may include a portion disposed below the cutting edge.

Provided is a technology capable of reliably carrying out air cutting during oscillation machining for threading regardless of oscillation phase differences. This machine tool control device 1 comprises: a condition acquisition unit 11 for acquiring, as a precondition, one or two pieces of information among three pieces of information, namely, an oscillation phase difference, information regarding a workpiece radial cut depth, and information regarding a radial oscillation amplitude of the workpiece; an air cut amount acquisition unit 12 for acquiring a specified air cut amount indicating the degree of air cut in the oscillation direction; and a machining control unit 13 for determining (a) piece(s) of information not acquired by the condition acquisition unit 11 among the three pieces of information on the basis of the precondition and carrying out machining control such that an air cut amount based on the interval between the n-th threading path and a threading path subsequent to the n-th path matches the specified air cut amount.