The invention relates to a tool part adapted to be connected to a tool counterpart, wherein the tool part comprises a centering portion and an axial stop, and wherein the tool part comprises a plug-rotation portion adapted to cooperate with a plug-rotation counterpart portion of the tool counterpart to connect the tool part to the tool counterpart.

A machining tool includes a holder and a cutting head which can be screwed into the holder. The cutting head includes a cutting-edge region and a coupling region. The coupling region includes a flat contact area facing the holder, a cylindrical thread carrier with an external thread adjoining the flat contact area, and a clamping cone adjoining the thread carrier. The holder includes a planar counter-contact area disposed adjacent the flat contact area of the coupling region, a cylindrical internal thread adjoining the planar counter-contact area, and a hollow-conical cone contact area next to the internal thread.

A head replacement-type cutting tool having a holder provided at the attachment hole with the fitting part formed in a tapered shape, and the leading end face is perpendicular to the central axis. The attachment part formed in a tapered shape protrudes on the cutting head from the rear end face perpendicular to the central axis of the cutting part. The cutting head is attached to the holder in such a manner that the attachment part is fitted into the fitting part by screwing the female thread part with the male thread part and the leading end face is in contact with the rear end face. The inner diameter to outer diameter ratio d/D1 which is a ratio of the inner diameter d of the fitting part before being fitted in relation to the outer diameter D1 of the leading end part of the holder is from 0.5 to 0.8.

A multi-part modular tool rotatable about a longitudinal tool axis (A), comprising: a machining head; a first holding element comprising a body elongated along the longitudinal axis (A) of the tool, in which a passage extends along the longitudinal axis (A) of the tool; a second holding element which can extend in the passage of the first holding element; wherein the machining head can be connected to the second holding element in such a way that the machining head is fixed firmly to the first holding element at least in the axial direction (A) and/or in the radial direction (R), and wherein the passage of the first holding element and the second holding element are adapted to one another such that during a connection process in which the machining head is connected to the second holding element, the second holding element is movable relative to the first holding element.

A rotary cutting tool includes a replaceable cutting head and a tool holder. The replaceable cutting head includes a forward cutting portion and a rearward mounting portion. The mounting portion includes a male coupling member that includes an external thread defined by external inner and outer cylinders. The external thread has concavely curved external thread roots which each merge with a respective straight external loaded surface at a first external root point. The first external root point is spaced apart from the external inner cylinder by a first external radial distance. The first external radial distance is greater than a third and less than two thirds of the external thread height. The tool holder includes a female coupling member that includes an internal thread. When the rotary cutting tool is in a locked position, the external thread is threadingly engaged with the internal thread.

Disclosed is an assembling and centering structure for a processing tool, the structure having a clamping handle (10), a processing head (20), and a fastening member (30) for connecting and fixing the clamping handle (10) and the processing head (20). An end face accommodation groove (100) of the clamping handle (10) is formed with a concave part (11) and a centering hole (12). The processing head (20) is formed with a convex part (211) and a centering post (222), the convex part (211) matches the concave part (11), and the centering post (222) matches the centering hole (12). Thus, it can be ensured that after assembly, the central axis of rotation of the clamping handle (10) is in a straight line with the central axis of rotation of the processing head (20).

A rotary cutting tool includes a replaceable cutting head and a tool holder. The replaceable cutting head includes a forward cutting portion and a rearward mounting portion. The mounting portion includes a male coupling member that includes a straight external thread. The tool holder includes a female coupling member that includes a conical internal thread. When the rotary cutting tool is in a locked position, the external thread is threadingly engaged with the internal thread.

Disclosed is an assembling and centering structure for a processing tool, the structure having a clamping handle (10), a processing head (20), and a fastening member (30) for connecting and fixing the clamping handle (10) and the processing head (20). An end face accommodation groove (100) of the clamping handle (10) is formed with a concave part (11) and a centering hole (12). The processing head (20) is formed with a convex part (211) and a centering post (222), the convex part (211) matches the concave part (11), and the centering post (222) matches the centering hole (12). Thus, it can be ensured that after assembly, the central axis of rotation of the clamping handle (10) is in a straight line with the central axis of rotation of the processing head (20).

A cutting tool comprises a shank having an insertion portion protruding from a shank main body, a head in which an insertion hole into which the insertion portion is inserted is formed, and a spacer disposed in a gap between the shank main body and the head. The insertion portion has a tapered outer circumferential surface which gradually decreases in diameter from the other side toward one side in the axial direction. The insertion hole has a tapered inner circumferential surface coming into surface contact with the tapered outer circumferential surface. A head end surface of the head which faces the other side in the axial direction comes into surface contact with a surface facing one side in the axial direction of the spacer.

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).