A rotating tool includes a tool body which rotates around an axial line, four or more chip discharge grooves which are formed on an outer periphery of the tool body with gaps therebetween in a circumferential direction, and a plurality of cutting inserts which are arranged in multiple stages along the chip discharge grooves. In a cross-sectional view perpendicular to the axial line, when a center angle formed between a pair of virtual straight lines which connects each of the cutting edges of the cutting inserts disposed in a pair of chip discharge grooves adjacent to each other in the circumferential direction and the axial line to each other is defined as an angle, a plurality of angles formed around the axial line include one maximum angle (max), one minimum angle (min), and two or more angles other than the angle (max) and the angle (min).

Described is an end mill with four straight front cutting edges arranged on a front side and a corresponding number of circumferential cutting edges that each emanate from the outer nose of the front cutting edges and are separated from each other by flutes. One of the front cutting edges passes over into a second cutting edge via a free surface intersecting line. The additional front cutting edges lying between the latter in the cutting direction are offset relative to each other by a first angular pitch of 180, and end before the middle. So that the end mill can be used in an especially advantageous manner for incorporating dimensionally and positionally precise pilot holes or chamfering curved work piece surfaces, the first front cutting edge is offset relative to the second front cutting edge in the cutting direction by a second angular pitch ranging between 173 and 177, preferably between 174 and 176, wherein the first front cutting edge is offset relative to the next additional front cutting edge in the cutting direction by a third angular pitch ranging between 90 and 94, preferably between 91 and 93.

A cutting insert including first cutting edges and second cutting edges respectively formed in a first end surface and a second end surface which are opposed to each other; at least one groove formed in a peripheral side surface which connects the first end surface and the second end surface; and, while one end of the groove reaches the first end surface, another end thereof reaches the second end surface, and an opening width in the first end surface is different from an opening width in the second end surface.

A rotating tool includes a tool body having an axis of rotation and a first recess for receiving an ID chip having a first mass and a first exterior geometry. The tool includes a dummy chip receivable in the first recess and the tool is rotationally balanced with the dummy chip in the first recess, wherein after balancing the dummy chip is removed and the ID chip is insertable in the first recess.

A tool for machining work pieces is disclosed. In order to provide a tool which exhibits only very small vibrations during operation, the tool body of the tool has a cavity in which a multiplicity of hollow structural elements having an outer closed shell, within which at least one solid particle or a hollow body is arranged in a freely movable manner, are accommodated.

An anti-vibration damper for tools for machining of metallic work pieces is provided. For improving the damping in order to be more effective under rough includes a vibration damping device received in a hollow cylindrical space of a tool member. The vibration damping device includes a plurality of rotationally symmetrical stacked on top of each other to form a stack. A part of mutually facing upper and lower surfaces of adjacent members is spaced at a distance from each other by elastically deformable elements. The outer diameter of the stack is smaller than the inner diameter of the hollow cylindrical space of the tool member, thereby providing a cylindrical gap, which is substantially filled with spherical balls, wherein clear gap width between the inner diameter of the hollow cylindrical space and the common outer diameter of the stack deviates from any integer sum of the ball diameters.

A milling machine includes a spindle which is arranged to receive a tool holder and in use to cause rotation of the tool holder within the spindle. A portion of the spindle housing surrounding the tool holder is provided with at least one pair of opposing damping units.

To provide a machine tool and a control device for the machine tool that can smoothly cut a workpiece while segmenting chips by feeding a cutting tool in a feed direction while reciprocally vibrating the cutting tool along the feed direction on the basis of a condition set by a user. The machine tool (100) or the control device (C) includes the control section (C1) that determines a number of rotations of the relative rotation and a number of vibrations of the reciprocal vibration per rotation of the relative rotation when the workpiece (W) is machined in accordance with a vibration frequency dependent on a period in which an operating instruction can be executed.

An end mill includes a plurality of teeth and flutes. The teeth and their associated flutes include one or more correlated physical parameters. One such correlated parameter is that, at an axial location in a front half of an effective cutting length, at least one tooth of the plurality of teeth has a rake angle smaller than an average rake angle value of the plurality of teeth, and, at the same axial location, a flute preceding each such tooth has a helix angle larger than an average helix angle value of the plurality of flutes.

A bur with features that minimize the application of substantially identical forces to the tissue against which the bur is applied. One of these features is the arrangement of the flutes so that one pair of flutes projects outwardly from the tip at an acute angle that is greater than the angle at which the other flutes project outwardly from tip. Consequently at the equator of the bur head, the location along the bur head where the bur head has a maximum diameter, the flutes define a perimeter that is non-circular in shape.