A variable radius gash geometry may be provided on a variety of rotary cutting tools. The rotary cutting tools extend along a longitudinal axis, from a shank towards a cutting face that engages a material to be cut during a plunge or ramp operation, and a plurality of gashes may be provided in the cutting face of the rotary cutting tool. The gashes may each be a full radius gash, and the radius defining each of the gashes may be unique or different from one another and tangent to an axial rake face and clearance face surrounding the gash.

An indexable rotary cutting tool and insert is capable of performing a high-accuracy cutting process with high efficiency. A twist angle of an outer peripheral cutting edge of the tool has a positive value, an axial rake angle of the cutting edge of a corner R of the tool at a boundary point between the cutting edge of the corner R and the outer peripheral cutting edge has a positive value, the axial rake angle of the cutting edge of the corner R at a reference point has a negative value, and the radial rake angle at least between the boundary point and the reference point in an entire edge length region of the cutting edge of the corner R has a negative value. The radial rake angle at the reference point is smaller than the radial rake angle at the boundary point.

A variable radius gash geometry may be provided on a variety of rotary cutting tools. The rotary cutting tools extend along a longitudinal axis, from a shank towards a cutting face that engages a material to be cut during a plunge or ramp operation, and a plurality of gashes may be provided in the cutting face of the rotary cutting tool. The gashes may each be a full radius gash, and the radius defining each of the gashes may be unique or different from one another and tangent to an axial rake face and clearance face surrounding the gash.

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.

A rotary cutting tool may include a cylindrical body having a cutting portion that extends longitudinally along an axis of the cylindrical body towards an axial end of the cylindrical body. A cutting face may be provided at the axial end, the cutting face having a plurality of end cutting edges associated with a plurality of gash grinds in the cutting face, wherein each gash grind from the plurality of gash grinds is defined by a different constant radius such that of each end cutting edge from the plurality of end cutting edges is of equal length.

An indexable rotary cutting tool comprising, a twist angle of the outer peripheral cutting edge having a positive value, an axial rake angle of the cutting edge of the corner R at a boundary point between the cutting edge of the corner R and the outer peripheral cutting edge has a positive value, the axial rake angle of the cutting edge of the corner R at the reference point has a negative value, at least the radial rake angle in a region between the boundary point and the reference point in an entire edge length region of the cutting edge of the corner R has a negative value, and the radial rake angle of the cutting edge of the corner R at the reference point is smaller than the radial rake angle of the cutting edge of the corner at the boundary point.

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.