The present invention relates to a tool (10) for machining a workpiece, comprising a cutting head (12) which comprises a sleeve (16) and a cutting element (18) which is fixed to the sleeve (16), and comprising a holder (14) to which the cutting head (12) can be detachably fixed. In an assembled state of the tool (10), the cutting head (12) and holder (14) are screwed to each other via an internal thread (40) which is arranged in the sleeve (16) and an external thread (42) which corresponds thereto and which is arranged on the holder (14). In addition, in the assembled state of the tool (10), the cutting head (12) and holder (14) contact each other along a first axial bearing surface (36) which is arranged on the sleeve (16) and a second axial bearing surface (38) which corresponds thereto and which is arranged on the holder (14), and along a first conical bearing surface (44) which is arranged on the sleeve (16) and a second conical bearing surface (46) which corresponds thereto and which is arranged on the holder (14).

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.

A main body (3) of a replaceable-tip cutting tool (1) includes a cylinder-shaped cylindrical portion (32) made from a first metal material and extending in an axial direction, and with a female thread portion (33) provided on an inner circumference (40) of the cylindrical portion (32) and capable of being screwed together with a male threaded portion (24) of a cutting head (2). The female thread portion (33) includes a first female thread portion (34) and a second female thread portion (35). The first female thread portion (34) is a portion between a top of a female thread crest (37) of the female thread portion (33) and a portion of the female thread portion (35) that is on the female thread crest (37) side of a female thread root (36) and on the female thread root side of a portion corresponding to an effective diameter of the female thread portion (33). The first female thread portion (34) is made from a second metal material that is different from the first metal material. The second female thread portion (35) is continuous with the inner circumference (40) of the cylindrical portion (32). The second female thread portion is a remaining portion of the female thread portion excluding the first female thread portion. The second female thread portion (35) is made from the first metal material.

A cutter holder structure comprises a cutter arbor and a connecting shaft having a tapered section at one end thereof. One end of the tapered section is formed with a first inner screw hole, and another end of the tapered section is formed with a second inner screw hole. The connecting shaft further has a horizontal positioning hole that penetrates through the connecting shaft. Two ends of the positioning hole are formed with cylindrical holes. A reduced hole is defined between the cylindrical holes. A nut has a third inner screw hole at one end and an axial hole at another end. The nut further has a horizontal countersink hole and a horizontal fourth inner screw hole. An eccentric distance is defined between a center of the countersink hole and a center of the fourth inner screw hole. A screw is inserted through the countersink hole and locked into the fourth inner screw hole.

The present invention relates to a tool (10) for machining a workpiece, comprising a cutting head (12) which comprises a sleeve (16) and a cutting element (18) which is fixed to the sleeve (16), and comprising a holder (14) to which the cutting head (12) can be detachably fixed. In an assembled state of the tool (10), the cutting head (12) and holder (14) are screwed to each other via an internal thread (40) which is arranged in the sleeve (16) and an external thread (42) which corresponds thereto and which is arranged on the holder (14). In addition, in the assembled state of the tool (10), the cutting head (12) and holder (14) contact each other along a first axial bearing surface (36) which is arranged on the sleeve (16) and a second axial bearing surface (38) which corresponds thereto and which is arranged on the holder (14), and along a first conical bearing surface (44) which is arranged on the sleeve (16) and a second conical bearing surface (46) which corresponds thereto and which is arranged on the holder (14).

A screwing tool includes a tool head and a tool shaft having an external thread. A first support section is disposed between the tool head and the external thread, and a second support section is disposed between the external thread and a free end of the tool shaft. The second support section has radially outwardly projecting supporting elements that are disposed at a distance from each other in the circumferential direction.

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.

A main body (3) of a replaceable-tip cutting tool (1) includes a cylinder-shaped cylindrical portion (32) made from a first metal material and extending in an axial direction, and with a female thread portion (33) provided on an inner circumference (40) of the cylindrical portion (32) and capable of being screwed together with a male threaded portion (24) of a cutting head (2). The female thread portion (33) includes a first female thread portion (34) and a second female thread portion (35). The first female thread portion (34) is a portion between a top of a female thread crest (37) of the female thread portion (33) and a portion of the female thread portion (35) that is on the female thread crest (37) side of a female thread root (36) and on the female thread root side of a portion corresponding to an effective diameter of the female thread portion (33). The first female thread portion (34) is made from a second metal material that is different from the first metal material. The second female thread portion (35) is continuous with the inner circumference (40) of the cylindrical portion (32). The second female thread portion is a remaining portion of the female thread portion excluding the first female thread portion. The second female thread portion (35) is made from the first metal material.

A system is proposed that is made up of a tool holder 1, a collet 15 with a clamping nut 19, and a tool insert 27, in which the collet 15 and the tool insert are fixed and positioned on various function surfaces within the tool holder 1. Nevertheless, the clamping means are the same, namely a thread on the tool holder 1.

A device for holding and securing a tool, in particular, a drill bit, on a machine tool, for example, a core drill, including an output shaft for transmitting a torque generated in the machine tool to the tool; and a union nut positioned around the output shaft for detachably connecting the output shaft to an attachment end of the tool. The output shaft includes a locking ring and the union nut includes a washer disk, as well as an attenuator, the washer disk being positioned between the locking ring and the attenuator.