A drilling tool, in particular a reamer, for drilling out a workpiece core bore to a nominal diameter by means of a main blade formed on a drill body is disclosed. The main blade has a radially external cutting edge which extends along a drill-body longitudinal axis as far as a blade corner arranged at the drill tip, wherein during the drilling-out operation, the drilling tool is drivable into the workpiece core bore with a rotary movement and a feed movement. The drilling tool has at least one groove blade which is arranged so as to precede the blade corner of the main blade in the direction of rotation of the tool. During the drilling-out operation, the groove blade produces a groove in the inner wall of the core bore drilling, the blade corner of the main blade being guided in the groove with an at least reduced cutting load.

A machining tool is a machining tool rotated about an axis and is provided with a machining blade portion having a rake face and a machining blade, wherein in a case where the rake face faces and is parallel to an virtual plane including the axis, the rake face is arranged at a position shifted from the virtual plane in the direction opposite to the rotational direction of the machining tool.

A rotary tool may include a base. The base may be extended from a first end to a second end. The base may include a first part and a second part. The first part may include the first end. The second part may have a larger outer diameter than the first part. The first part may include a first flute. The second part may include a second flute. In a first cross section of the first part, the first flute may include a first bottom part. A center of a first imaginary circle overlapping with the first bottom part may be located outside a circumscribed circle of the first part. In a second cross section of the second part, the second flute may include a second bottom part. A center of the second imaginary circle overlapping with the second bottom part may be located inside a circumscribed circle of the second part.

A machining tool is a machining tool rotated about an axis and is provided with a machining blade portion having a rake face and a machining blade, wherein in a case where the rake face faces and is parallel to an virtual plane including the axis, the rake face is arranged at a position shifted from the virtual plane in the direction opposite to the rotational direction of the machining tool.

A machine reaming tool includes a shank and an interchangeable head assembled on the shank. The interchangeable head on a side that faces the shank includes at least one head groove and at least one head ridge. The shank on a side that faces the interchangeable head includes at least one shank groove and at least one shank ridge. In the assembled condition, the at least one head groove engages into the at least one shank ridge and the at least one shank groove engages into the at least one head ridge.

A drilling tool, in particular a reamer, for drilling out a workpiece core bore to a nominal diameter by means of a main blade formed on a drill body is disclosed. The main blade has a radially external cutting edge which extends along a drill-body longitudinal axis as far as a blade corner arranged at the drill tip, wherein during the drilling-out operation, the drilling tool is drivable into the workpiece core bore with a rotary movement and a feed movement. The drilling tool has at least one groove blade which is arranged so as to precede the blade corner of the main blade in the direction of rotation of the tool. During the drilling-out operation, the groove blade produces a groove in the inner wall of the core bore drilling, the blade corner of the main blade being guided in the groove with an at least reduced cutting load.