Broadly contemplated herein, in accordance with at least one embodiment, is a multi-flute end mill configuration that maintains circumferential spacing between the rake surface and clearance surface adjoining two adjacent end face cutting edges, respectively, regardless of the number of flutes and the desired end face configuration.

In an end mill body made of ceramic, a corner R rake face is formed in such a manner as to contain a point B and at least a region B, not a region A located on a side toward an end cutting edge. In other words, a first end portion of a cutting edge on a peripheral edge portion of the corner R rake face is formed on a peripheral edge of the region B of a corner R cutting edge, and a second end portion of the cutting edge reaches at least the point B. As a result, partial breakage of the corner R cutting edge is unlikely to occur in the course of cutting. That is, since the corner R rake face is formed in such a manner as to start from the first end portion located apart from a point A, which is the intersection of the end cutting edge and the corner R cutting edge, and such that the second end portion reaches the point B, a large cutting load is unlikely to be imposed on the starting point of the corner R rake face. Therefore, the corner R cutting edge is unlikely to be chipped.

A milling tool comprising a cylindrical shaft part, which has a central axis and which is followed by a cylindrical cutting part comprising at least three circumferential cutting edges, which run helically and which are separated from one another by chip grooves. The circumferential cutting edges continue via cutting edge corner regions in end cutting edges, which run essentially radially and which subsequently slope away from the milling cutter face towards the central axis from radially outer end cutting edge sections, in each case with a cutting edge section, which is formed by ground-in end pockets. The cutting edge section slopes continuously all the way to the central axis. In the region of the milling cutter core, it is formed by a point thinning, which is introduced into the end pocket and by means of which a center cutting edge is created. Also, a method for producing the milling tool.

A rotary cutting tool includes a shaft having and outer surface and having a longitudinal axis, a plurality of helical flutes formed in the shaft about the longitudinal axis, a plurality of helical cutting edges formed at an interface with the outer surface and a respective helical flute about the longitudinal axis, and a plurality of end cutting edges located on an axial distal end of a cutting portion of the shaft, the end cutting edges being contiguous with a corresponding one of the plurality of helical cutting edges and forming a corner in the transition between each of the end cutting edges and the corresponding one of the plurality of helical cutting edges. A hone edge extends along a portion of each of the end cutting edges, the associated corner and a portion of the corresponding one of the plurality of helical cutting edges.

In an indexable rotary cutting tool of the present invention, a cutting edge portion of an insert includes a peripheral cutting edge, a bottom cutting edge, a cutting edge of a corner R, and a chamfered surface, a radial rake angle () of the cutting edge of the corner R has a negative value in an entire edge length region of the cutting edge of the corner R, and the radial rake angle () becomes a minimum value at an intermediate portion located between a pair of boundary points (P, Q) in the cutting edge of the corner R.

The invention relates to a ring-shaped tool for processing a workpiece, wherein the tool has a fastening region which is centred with its ring shape for fastening to a rotatable drive shaft, wherein the tool has cutting teeth and the teeth extend on both sides of the tool in each case from the head region of the tool in the direction of the fastening region, the teeth on one side having a right-hand twist and providing right-hand cutting, and the teeth on the other side having a right-hand twist and providing left-hand cutting.

The rotary cutting tool of the invention has helicoidal peripheral cutting edges with a wavy profile.

In an indexable rotary cutting tool of the present invention, a cutting edge portion of an insert includes a peripheral cutting edge, a bottom cutting edge, a cutting edge of a corner R, and a chamfered surface, a radial rake angle () of the cutting edge of the corner R has a negative value in an entire edge length region of the cutting edge of the corner R, and the radial rake angle () becomes a minimum value at an intermediate portion located between a pair of boundary points (P, Q) in the cutting edge of the corner R.

An object of the present invention is to provide helically fluted end mill with a diamond cutting surface. More particularly, it is an object of the present invention to provide a helically fluted end mill with helical grooves in the flutes that are filled with compacted polycrystalline diamond that can provide an effective cutting length based on the appropriate relationship between cutting length, diameter, the number of flutes, angle, and the number of polycrystalline diamond segments per flute.

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.