A cylindrical calibration head for the drilling of a shaft, includes three flutes arranged evenly around the circumference so that they are spaced one from the next by an angle of 120° with respect to a rotation with respect to the axis of the calibration head, the flutes allowing for the removal of chips and the passage of lubricant during drilling, each of the flutes including a machining insert of which the position in the flute can be adjusted using an adjusting cartridge.

According to one implementation, a drill includes the first cutting edges, the second cutting edges and a deflection reducer. The first cutting edges drill a prepared hole to a workpiece. The first cutting edges are formed in a tip side of the drill. The first point angle and each first relief angle of the first cutting edges continuously or intermittently decrease from the tip side toward a rear end side of the drill. The second cutting edges ream the prepared hole. The second cutting edges are formed at positions away in the rear end side from the first cutting edges. The second cutting edges have the second relief angles at a maximum diameter position. The deflection reducer reduces deflection of the second cutting edges. The deflection reducer is formed between the first cutting edges and the second cutting edges. The deflection reducer is inserted into the prepared hole.

The invention relates to a tool holder (2) for connecting a machining tool (4) having a depth-control stop (3) to a working spindle of a machine tool, having a spindle-side shaft part (6) and a receiving part (7) which supports the machining tool (4) and is connected in a rotationally fixed manner to the shaft part (6). The receiving part (7) is axially displaceable in the tool feed direction via a compression spring arrangement (21), that is supported on the shaft part (6), counter to a fixed stop (17a) on the shaft part (6) and can be displaced away from the fixed stop (17a) on the shaft part (6) during the impact of the depth stop (3) on a workpiece against the spring force of the compression spring device (21).

Provided is a taper reamer with which it is possible to achieve an improvement in machining accuracy and machining life. The taper reamer comprises a plurality of cutting edges each having a helical shape provided on the outer periphery of a cutting-edge portion having an external diameter being expanded from a front end toward a rear end thereof, wherein an intertooth angle, defined between each of a pair of the cutting edges adjacently arranged in a circumferential direction, is different from one another at any given reference position, and wherein the plurality of cutting edges each have a helix angle that is different from one another. As the plurality of cutting edges that are unequally partitioned each have the helix angle that is different from one another, a resonance during cutting can be prevented.

According to one implementation, a drill includes the first cutting edges, the second cutting edges and a deflection reducer. The first cutting edges drill a prepared hole to a workpiece. The first cutting edges are formed in a tip side of the drill. The first point angle and each first relief angle of the first cutting edges continuously or intermittently decrease from the tip side toward a rear end side of the drill. The second cutting edges ream the prepared hole. The second cutting edges are formed at positions away in the rear end side from the first cutting edges. The second cutting edges have the second relief angles at a maximum diameter position. The deflection reducer reduces deflection of the second cutting edges. The deflection reducer is formed between the first cutting edges and the second cutting edges. The deflection reducer is inserted into the prepared hole.

In order to achieve as highly accurate an alignment of the reamer as possible and therefore as high a drilled hole quality as possible during the precision machining of a drilled hole, the cutting edges of the reamer are divided into two cutting groups, the cutting edges of which are spaced apart with respect to one another in each case by an axial spacing from one another. Here, the axial spacing is selected in such a way that, at a predefined first, slower feed speed, merely the cutting edges of the first cutting edge group are in engagement with the workpiece and, at a higher, predefined second feed speed, all cutting edges are in engagement with the workpiece.

Provided is a taper reamer with which it is possible to achieve an improvement in machining accuracy and machining life. The taper reamer comprises a plurality of cutting edges each having a helical shape provided on the outer periphery of a cutting-edge portion having an external diameter being expanded from a front end toward a rear end thereof, wherein an intertooth angle, defined between each of a pair of the cutting edges adjacently arranged in a circumferential direction, is different from one another at any given reference position, and wherein the plurality of cutting edges each have a helix angle that is different from one another. As the plurality of cutting edges that are unequally partitioned each have the helix angle that is different from one another, a resonance during cutting can be prevented.

An anti-vibration device for the machining of a shaft includes a first fixed ring intended to be kept inside a shaft by a shoulder, the anti-vibration device including: at least one first external groove and at least one first external seal for forming at least one contact with the internal surface of the shaft; at least one first internal circumferential groove and at least one first internal seal for forming at least one contact with the external surface of the bar; an internal circumferential cavity that is able to cause the circulation of a fluid arriving through a first duct and leaving through a second duct, the first duct and second duct passing through the radial thickness of the anti-vibration device, the internal circumferential cavity making it possible to realize a vibration-damping function when a fluid passes through it.

In order to achieve as highly accurate an alignment of the frictional tool as possible and therefore as high a drilled hole quality as possible during the precision machining of a drilled hole, the cutting edges of the frictional tool are divided into two cutting groups, the cutting edges of which are spaced apart with respect to one another in each case by an axial spacing from one another. Here, the axial spacing is selected in such a way that, at a predefined first, slower feed speed, merely the cutting edges of the first cutting edge group are in engagement with the workpiece and, at a higher, predefined second feed speed, all cutting edges are in engagement with the workpiece.

In order to achieve as highly accurate an alignment of the frictional tool as possible and therefore as high a drilled hole quality as possible during the precision machining of a drilled hole, the cutting edges of the frictional tool are divided into two cutting groups, the cutting edges of which are spaced apart with respect to one another in each case by an axial spacing from one another. Here, the axial spacing is selected in such a way that, at a predefined first, slower feed speed, merely the cutting edges of the first cutting edge group are in engagement with the workpiece and, at a higher, predefined second feed speed, all cutting edges are in engagement with the workpiece.