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

A diamond coating includes a first diamond layer made of minute diamond particles and a second diamond layer made of coarse diamond particles: in a flank-face side diamond coating, a mean coat thickness d2 is not less than 3 m and not more than 25 m, a first diamond layer is formed on a surface side and a second diamond layer is formed on a tool base side: a rake-face side diamond coating is in a smaller range of 50 m or 1/10 of a tool diameter from a tip of a base cutting-edge part; in the rake-face side diamond coating, a mean coat thickness d1 is a smaller one in a range not less than 0 m and not more than 5.0 m or a range less than d2: and a boundary part between the first diamond layer and the second diamond layer.

The present invention relates to a cutting tool, which performs, like a drill or a ball end mill, cutting while rotating in a state in which the center of the tip end is in contact with a work material, and includes a wear-resistant layer formed at the tip end thereof, wherein a portion of the wear-resistant layer is selectively removed through tip end polishing from the center of the tip end of the drill or the ball end mill to a predetermined area, so as to restrain micro-brittle wear generated in an ultra-low speed region, and thus remarkably improving the cutting lifespan of the cutting tool such as the drill or the ball end mill.

The present invention relates to a cutting tool, which performs, like a drill or a ball end mill, cutting while rotating in a state in which the center of the tip end is in contact with a work material, and includes a wear-resistant layer formed at the tip end thereof, wherein a portion of the wear-resistant layer is selectively removed through tip end polishing from the center of the tip end of the drill or the ball end mill to a predetermined area, so as to restrain micro-brittle wear generated in an ultra-low speed region, and thus remarkably improving the cutting lifespan of the cutting tool such as the drill or the ball end mill.

A diamond coating includes a first diamond layer made of minute diamond particles and a second diamond layer made of coarse diamond particles: in a flank-face side diamond coating, a mean coat thickness d2 is not less than 3 m and not more than 25 m, a first diamond layer is formed on a surface side and a second diamond layer is formed on a tool base side: a rake-face side diamond coating is in a smaller range of 50 m or 1/10 of a tool diameter from a tip of a base cutting-edge part; in the rake-face side diamond coating, a mean coat thickness d1 is a smaller one in a range not less than 0 m and not more than 5.0 m or a range less than d2: and a boundary part between the first diamond layer and the second diamond layer.

A ball end mill according to the present invention includes an end mill body which is formed in a shaft shape, a plurality of convex arcuate end cutting edges which are disposed on a tip portion of the end mill body at intervals around an axis and form a hemispherical shape such that a rotational locus around the axis has a center on the axis, and a plurality of gashes which are respectively disposed to be adjacent to the plurality of end cutting edges in an end mill rotation direction around the axis. The plurality of end cutting edges includes a first end cutting edge longest among the plurality of end cutting edges, a second end cutting edge which is adjacent to the first end cutting edge in the end mill rotation direction and a third end cutting edge which is adjacent to the second end cutting edge in the end mill rotation direction.

In one aspect, elongated rotary cutting tools such as end mills are described herein which may provide one or more advantages over prior designs. For example, in some embodiments, cutting tools described herein can provide reduced wear rates at corner cutting edges, may permit high ramp angles during processing up to and including 45 ramp angles, and/or increased tool life.

A method is provided for the material-removing machining of fillets on a workpiece by means of a tool, more particularly a milling tool, which is guided over a fillet at a contact point. The invention is characterized in that the fillet is machined by means of a tool comprising a conical-convex cutting edge on a flank of the tool, wherein the tool, with the contact point on the conical-convex cutting edge, moves along at least one contact path running in the longitudinal direction of the fillet and the tool is inclined sideways in relation to the at least one contact path on the fillet such that a substantially sickle-shaped material engagement is formed in front of the contact point in the movement direction of the tool.

A milling tool for milling and/or drilling workpieces, which is rotatable in a direction of rotation about an axis of rotation during machining, comprising a milling head, which has a radius cutter that describes a portion in the form of a circular arc such that the milling head takes up a partially spherical, in particular a hemispherical volume, in rotation, a main body, which has a main feature in the form of a helical recess with respect to the rotation volume taken up by the rotating milling tool in order to form a conveying helix, wherein the main feature is provided with a cutting edge as main cutter, wherein the main feature has a smooth lateral surface arranged on the side facing away from the main cutter in the direction of rotation.

An end mill includes a bar-shaped body, a cutting edge, a gash, a first flute, and a second flute. The body extends from a first end to a second end along a rotation axis. The cutting edge is located at a side of the first end of the body. The gash is located adjacent to the cutting edge. The first flute surrounds the gash and spirally extends from the gash toward the second end. The second flute surrounds the first flute and spirally extends from the first flute toward the second end. A depth of the first flute is greater than a depth of the second flute in a cross section orthogonal to the rotation axis.