Drilling tool and method for producing a borehole

A drilling tool for producing a bore with a cylindrical inner wall, wherein:

• a) the drilling tool is rotatable in a rotary movement with a predetermined rotational direction (VD) about a tool axis (A) extending through the drilling tool and at the same time is movable in an axial forward movement (VB) in a forward direction axially to the tool axis;
• b) the drilling tool comprises at least one drilling area arranged in a forwardly located region of the drilling tool at a forward or free end, but not having a thread forming region;
• c) the drilling area has a number n of drilling edges which are arranged offset to each other in the rotational direction, where n is a natural number with n≥2;
• d) a chip divider is arranged on each of the n drill cutting edges, which chip divider forms an interruption of the respective drill cutting edge;
• e) the axial depth of each chip divider measured in the axial direction to the tool axis is selected from a range of 0.5/n to 1.1/n multiplied by the axial feed of the drilling tool per revolution;
• f) the radial distances of the chip dividers from the tool axis are different at at least two of the n drill cutting edges in such a way that, in a rotational projection in the predetermined rotational direction about the tool axis, a chip divider on a first drill cutting edge is followed by a cutting edge region of a subsequent second drill cutting edge;
• g) each drill cutting edge is formed on an associated web;
• and
• h) for at least one free surface (63, 64) adjoining each drill cutting edge on each web, on an end face of the web, a free angle of the free surface between the free surface and a transverse plane running perpendicular to the tool axis (A) is selected in a radially outer range of between 5° to 15°, and increases radially inwards to a value of at most 40°.

A drilling tool for producing a bore with a cylindrical inner wall, wherein:

• a) the drilling tool is rotatable in a rotary movement with a predetermined rotational direction (VD) about a tool axis (A) extending through the drilling tool and at the same time is movable in an axial forward movement (VB) in a forward direction axially to the tool axis;
• b) the drilling tool comprises at least one drilling area arranged in a forwardly located region of the drilling tool at a forward or free end, but not having a thread forming region;
• c) the drilling area has a number n of drilling edges which are arranged offset to each other in the rotational direction, where n is a natural number with n≥2;
• d) a chip divider is arranged on each of the n drill cutting edges, which chip divider forms an interruption of the respective drill cutting edge;
• e) the axial depth of each chip divider measured in the axial direction to the tool axis is selected from a range of 0.5/n to 1.1/n multiplied by the axial feed of the drilling tool per revolution;
• and
• f) a corner break (70) is provided on the outer areas of the drill cutting edges, wherein:
• a corner break angle (β) of the corner break to the radial direction lies in the range between 15° and 30°, and
• a radially measured corner break width of the corner break is between 0.05 mm and 0.4 mm.