A tool holder having a main body for coupling the tool holder to the spindle of a machine tool and having a clamping surface connected thereto for clamping a tool, characterized in that the tool holder has at least one portion shaped in one piece by primary shaping, which in its interior has one or more cavities that form an enclave in the portion shaped by primary shaping.

A reducing sleeve for fastening a machining tool in a tool holder is described. The reducing sleeve includes a reducing sleeve body, which has a first tool-side end and a second tool holder-side end. In addition, at least one coolant supply channel is provided in the reducing sleeve body. In one embodiment, a safety unit with a pull-out safety geometry has a sealing element, such as an O-ring, to selectively direct coolant through coolant holes in the safety unit and the at least one coolant supply channel or alternatively through a central coolant channel. In this embodiment, a multifunctional interface, and additional O-ring and a sealing unit are not required. A modular reducing sleeve assembly includes a reducing sleeve and a safety unit as separate parts. In addition, a machining assembly including a tool holder, a reducing sleeve, and a machining tool is described.

An extension assembly configured to permit a user to drill a hole through inaccessible areas in a wall is disclosed. The extension assembly includes a flexible, solid core rod having first and second ends and a holding means. The rod is configured to extend through a hole in a wall cavity and flex therein to position a tool bit at an inaccessible location in the wall cavity and permit a user to drill a hole through a substrate at the inaccessible location. The holding means is secured to the second end of the rod for releasably holding a tool bit for rotation with the rod and includes a sleeve adapted to slide axially along a body of the holding means between a secured position where a tool bit is securely held within the holding means and a release position where the tool bit is released from the holding means.

A system is disclosed for releasable coupling of a hole saw to a drill arbor. The system includes an elongate drill arbor configured at a first end to be clamped in a drill chuck of a drill, and a hole saw adapter provided with a longitudinal bore in which the drill arbor can be received so that an inner surface of the longitudinal bore of the hole saw adapter is mounted slidably on an outer surface of the drill arbor in the longitudinal direction of the drill arbor. The drill arbor includes an actuator member and at least one retaining element co-acting therewith. The inner surface of the longitudinal bore of the hole saw adapter is provided with a recess into which the retaining element of the drill arbor can protrude.

A power skiving tool comprising a shank that extends along a longitudinal axis of the tool, and a cutting head that is arranged at an end face of the shank. The cutting head comprises a plurality of circumferentially arranged teeth, wherein, when viewed in a cross-section orthogonal to the longitudinal axis, each of the teeth comprises a convexly rounded contour, which at a first end transitions either directly or via a first concave transition contour into the convexly rounded contour of a first adjacent tooth of the plurality of teeth and at a second end opposite the first end transitions either directly or via a second concave transition contour into the convexly rounded contour of a second adjacent tooth of the plurality of teeth. A width of each tooth of the plurality of teeth, measured in the cross-section as a distance between the first end and the second end, is greater than a height of the respective tooth, measured in the cross-section orthogonal to the width and centrally between the first end and the second end.

Disclosed is a mounting device (6) including a receiving opening (8) with a circular inner locating surface (10) which is coaxial with the axis of rotation (3) and serves for engagement with radially outer vertices (24) of the polygon profile of a holding pin (23). Arranged adjacent to the inner locating surface is a positioning disk (14) which has an opening (15) coaxial with the axis of rotation (3) and of such polygonal shape and size that the polygon profile of the holding pin (23) engaging in the opening (15) is supported in the opening (15) in a manner preventing relative rotation.

A hole saw including a plurality of sidewall openings is provided. The sidewall openings are shaped and grouped in patterns that improve debris ejection of the hole saw and that allow for easy access to the interior of the hole saw for manual debris removal by the user. The opening groups are space from each other by larger uninterrupted areas such that the hole saw has a high strength despite the number and size of openings provided in the saw sidewall.

A hole saw including a plurality of sidewall openings is provided. The sidewall openings are shaped and grouped in patterns that improve debris ejection of the hole saw and that allow for easy access to the interior of the hole saw for manual debris removal by the user. The opening groups are space from each other by larger uninterrupted areas such that the hole saw has a high strength despite the number and size of openings provided in the saw sidewall.

An integrated drill chuck for installing mine roof bolts includes a single integrated piece, the single integrated piece including a body defining a receiving cavity, where the receiving cavity is configured to receive and secure a bit having a square-shaped end and a bit having a hex-shaped end. A drill for installing mine roof bolts is also disclosed. A method for installing mine roof bolts is also disclosed.

A tool holder having a main body for coupling the tool holder to the spindle of a machine tool and having a damping surface connected thereto for clamping a tool, characterized in that the tool holder has at least one portion shaped in one piece by primary shaping, which in its interior has one or more cavities that form an enclave in the portion shaped by primary shaping.