Tool holder assembly and method of manufacturing a tool holder

A method for manufacturing a tool holder for holding a tool for machining workpieces, the method comprising:

• providing a tool holder blank;
• forming a tool holder interface on the tool holder blank, wherein the tool holder interface is configured to fixate the tool holder to a holder shaft configured to be clamped in a machine tool, wherein the tool holder interface comprises:
• a tool holder plane surface oriented transversely to a tool holder longitudinal axis and configured to come into abutment against a holder shaft plane surface provided at the holder shaft to establish a defined relative position in a longitudinal direction between a tool mount of the tool holder blank and the holder shaft,
• a tool holder cone section having a polygonal cross-section and configured to come into engagement with a correspondingly polygonal holder shaft cone section in order to establish a defined relative position in a tangential direction between the tool mount and the holder shaft, and
• a tool holder cylinder section configured to act together with a corresponding holder shaft cylinder section, wherein the tool holder cylinder section comprises a radial recess comprising a slanted surface oriented at an angle and configured to interact with a longitudinal clamping screw of the holder shaft to axially tighten the tool holder cylinder section with the holder shaft cylinder section;
• inserting the tool holder blank into a reference holder shaft such that the tool holder plane surface abuts a holder shaft plane surface of the reference holder shaft;
• and
• machining the tool mount to finish the tool holder, wherein the tool mount is configured to secure the tool.

A holder shaft for a tool holder, the holder shaft comprising:

• a holder shaft body comprising a shaft section configured to be clamped in a clamping device of a machine tool, and further comprising a holder shaft interface for fastening a tool holder to the holder shaft body, wherein the holder shaft interface comprises:
• a holder shaft plane surface oriented transversely to a tool holder longitudinal axis and configured to come into abutment against a tool holder plane surface provided at the tool holder in order to establish a defined relative position in a longitudinal direction between the tool holder and the holder shaft;
• a holder shaft cone section having a polygonal cross-section and configured to come into engagement with a correspondingly polygonal tool holder cone section in order to establish a defined relative position in tangential direction between the tool holder and the holder shaft;
• and
• a holder shaft cylinder section configured to act together with a corresponding tool holder cylinder section, wherein the holder shaft cylinder section comprises:
• a radial threaded bore configured to receive a longitudinal clamping screw to engage in a radial recess of the tool holder to axially tighten the tool holder cylinder section with the holder shaft cylinder section, and
• a radial clearance recess that:
• extends over an axial length which is smaller than an axial length of the holder shaft cylinder section,
• extends over an angular range of less than 360°, and
• overlaps with the radial threaded bore in a circumferential direction.

A holder shaft for a tool holder, the holder shaft comprising:

• a holder shaft body comprising a shaft section configured to be clamped in a clamping device of a machine tool, and further comprising a holder shaft interface for fastening a tool holder to the holder shaft body, wherein the holder shaft interface comprises:
• a holder shaft plane surface oriented transversely to a tool holder longitudinal axis and configured to come into abutment against a tool holder plane surface provided at the tool holder in order to establish a defined relative position in a longitudinal direction between the tool holder and the holder shaft;
• a holder shaft cone section having a polygonal cross-section and configured to come into engagement with a correspondingly polygonal tool holder cone section in order to establish a defined relative position in tangential direction between the tool holder and the holder shaft;
• and
• a holder shaft cylinder section configured to act together with a corresponding tool holder cylinder section, wherein the holder shaft cylinder section comprises:
• a radial threaded bore configured to receive a longitudinal clamping screw to engage in a radial recess of the tool holder to axially tighten the tool holder cylinder section with the holder shaft cylinder section, and
• a radial clearance recess that has, in a cross-section perpendicular to the holder shaft plane, the shape of a sickle.