A boring bar has a generally cylindrical elongate tool body has a proximal end for mounting to drive unit and a distal end for attachment to a tool head. A passageway extends longitudinally along the central axis of the elongate tool body. A plurality of longitudinally extending cavities are disposed annularly about the tool body. A compressive material is disposed in each of the cavities. An adjustable compression fitting is disposed in at least one end of each of the cavities, where each of the compression fitting can be adjusted to change compression of the material disposed in a respective cavity.

A cutting tool such as a drill (1) in which a coating layer (6) is provided to the surface of a base body (5) having a rod shape, which is equipped with a cutting edge (2) provided to at least the tip portion (A) of the base body (5) having a rod shape and a chip discharge section (4) provided adjacent to the cutting edge (2) so as to extend rearwards (i.e., towards the rear end) from the tip portion (A), the coating layer (6) comprising a mixture phase of diamond and graphite and having a diamond content ratio which is lower in a rear end located 10 mm rearward from the tip than in the tip portion (A).

A workpiece accommodation device for purposes of accommodating a workpiece and for use in a device for the machining of a workpiece with: a tool mounting for purposes of accommodating the tool, a workpiece accommodation device for purposes of accommodating the workpiece, characterized in that during the machining process at least one first oscillation component can be introduced in a Z-direction, and an, in particular simultaneous, second oscillation component can be introduced in an X- and/or Y-direction by means of oscillation components.

A rotary tool for machining workpieces, comprising at least one main body with a clamping segment, a tool head comprising a cutting region, and at least one coolant channel for feeding a cooling and lubricating fluid into the cutting region. At least one partial surface section of the cutting region forms a hardened region, which covers and/or defines the coolant channel and is surface-hardened. A method for producing a rotary tool.