A tool, such as a hole saw, including an open end cap geometry is provided. The end cap includes spokes extending between a hub and a rim. A plurality of openings are defined between the spokes, hub and rim. The area of the openings is substantially large relative to the area of the end cap such that the end cap is relatively lightweight and provides access into the hole saw for debris removal. The spokes are shaped and positioned to provide strength to the end cap.

A tool attachment, in particular hole saw, for a power tool having a driving axle that is drivable in oscillation. The tool attachment including a connecting device with which the tool attachment is attachable to the power tool such that the driving axle thereof and a tool axis essentially coincide. A work area has teeth, with the work area being at least partially circular in design and adjoining a hollow, cylindrical base. Openings are formed in the base, the openings constituting at least 60%, at least 80%, or at least 90% of the area of the base.

An arbor for a hole saw includes an arbor shaft configured to be coupled to a power tool. The arbor shaft defines a longitudinal axis. The arbor also includes an arbor stem supported by the arbor shaft. The arbor stem includes at least one arm having a threaded portion configured to engage the hole saw. The arbor further includes an actuator supported by the arbor shaft. The actuator is operable to move the threaded portion of the at least one arm relative to the longitudinal axis.

The present disclosure relates to a tool holding arrangement (1, 1′, 1″) comprising a rotatable shaft (2, 2′, 2″) which is at least connectable to a tool driving power source (3) and comprises a first shaft thread (4, 4′). The tool holding arrangement (1, 1′, 1) comprises a thread insert (5, 5′) that comprises a first insert thread (6, 6′), adapted to engage the first shaft thread (4, 4′) so as to form a first thread arrangement (4, 6; 4′, 6′). The thread insert (5, 5′) comprises a second insert thread (7) that is adapted to engage a tool thread (8) of a tool holding device (9) that is arranged to be 2 screwed onto the second insert thread (7) so as to form a second thread arrangement (7, 8), the first thread arrangement (4, 6; 4′, 6′) having a higher pitch than the second thread arrangement (7, 8).

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 tool holder for a machine tool, in particular for a core drilling machine, having a hollow shaft which has, at one end for coupling to the drive of the machine tool, a connector and, at the other end, a receiving opening with a plurality of openings in which locking elements are accommodated which are radially adjustable between a clamping position and an release position for securing a tool accommodated in the receiving opening. A switching sleeve is provided, which is adjustably mounted on the hollow shaft between a first switching position and a second switching position, a first subset of the locking elements being provided in the first switching position for locking the tool in the receiving opening, and a second subset of the locking elements being provided in the second switching position for locking the tool in the receiving opening, while the adjustment of the respective remaining locking elements is deactivated.

A hole cutting tool with plug ejection includes a hole saw having a first central bore and an arbor having a second central bore along a central axis. The arbor is configured at one end to be coupled to a rotational drilling machine, and at the other end to be attached to the hole saw in a first cutting position and detached from the hole saw in a second ejection position. The hole cutting tool also includes a pilot guide having an ejection shoulder. The pilot guide is slidably disposed within the second central bore of the arbor and received through the first central bore of the hole saw. The pilot guide being configured to translate along the central axis between a first drilling position and the second ejection position.

Hole saw adapter (10) comprised of an adapter body (12) with a first end equipped with a spindle (14) for fastening to a drive unit, such as a drilling machine, and a second end to receive a hole saw (32) and a central drill (34), in which the adapter body (12) is extended and equipped with a longitudinally running axial groove (16) where the longitudinally running axial groove (16) is at least partially formed as a cross-wise through-running open slit in the adapter body (12). The central drill (34) is fasten to the inner axially displaceable holding part (22) so that it can be made loose, said inner axially displaceable holding part (22) can be displaced in the longitudinally running axial groove (16) in the adapter body (12) and is fastened to an external displacement part (18), as the external displacement part (18) surrounds the adapter body (12) and is set up for a forced axial displacement of the axially displaceable holding part (22) and the central drill (34) in the longitudinally running axial groove (16) for the pushing out of a core (40) that remains in the hole saw (32) after drilling.

A quick-changing brazed drill includes a drill body and a quick-changing joint. The drill body is connected to the quick-changing joint detachably, and a vent hole is provided at a connection point between the drill body and the quick-changing joint. The drill body has a cylindrical structure, an interior of a front end of the drill body is hollow, and an outer side of the front end of the drill body is provided with 2-6 grooves. The quick-changing joint includes a transition block and a rear cover; a rear end of the transition block is connected to the rear cover by an external thread; a snap-fit area is provided between the transition block and the rear cover; a middle portion of the transition block is provided with a first threaded hole and is connected to a rear end of the drill body.

A method for releasing a screw connection between a core drilling device and a drill bit, wherein the screw connection is released by application of torque spikes to the drive shaft of the core drilling device, these torque spikes coming into effect when the drive shaft is driven counter to the actual drilling direction of the core drilling device. A core drilling device with which the proposed method can be carried out is also provided. To this end, the core drilling device includes a drive shaft to which torque spikes can be applied, wherein the drive shaft can be driven in a drilling direction and a second direction of rotation which is opposite to the drilling direction. A core drilling device, in which the reversal of a direction of rotation of a drive shaft of the core drilling device and application of torque spikes to the drive shaft are combined with one another such that, as a result of the combination of the reversal of the direction of rotation and torque spikes, a screw connection between the core drilling device and a drill bit can be released.