A tool coupling includes a first member, having a male coupling portion extending along a first axis, and a second member, having a female coupling portion extending along a second axis. The male coupling portion has front and rear drive members defining male front and rear footprints in respective first and second transverse mating planes. The female coupling portion has front and rear drive passages defining front and rear peripheral profiles in respective first and second transverse passage planes. The front and rear drive members respectively occupy the front and rear drive passages, and at least one of the front and rear drive members prevents rotation of the second member about the second axis. On imaginary rotation of the front peripheral profile by any angle about the second axis and axial projection thereof, the front peripheral profile overlaps (i.e., at least partially crosses) the rear footprint.

Provided is a fastening structure having a wide application range and a high degree of freedom of design. A fastening structure includes: a head including a first end surface and a first screw part formed on the first end surface; and a shank including a second end surface and a second screw part formed on the second end surface and threadedly engaging with the first screw part. The first end surface includes a first principal surface oriented in an axial direction of the first screw part and a first step surface oriented in a rotational direction of the first screw part. The second end surface includes a second principal surface oriented in an axial direction of the second screw part and a second step surface oriented in a rotational direction of the second screw part. The first and second principal surfaces face each other and the first and second step surfaces face each other when the first screw part threadedly engages with the second screw part.

A tool holder has a main body and a holding pin onto which a rotary tool having a corresponding holding bore can be placed. At least one channel for transporting coolant or lubricant, the channel leading to the outer circumference of the holding pin, is arranged in the tool holder. In order to enable cooling of the cutting edges of the rotary tool without great production complexity, at least one longitudinal groove for conducting the coolant or lubricant in a longitudinal direction of the holding pin is arranged on the outer circumference of the holding pin.

A drill tip may include a first part and a second part. The first part includes a cutting edge located at a side of a first end, and a recess located at a side of a second end, where the first end is one side of a central axis and the second end is another side of the central axis. The second part includes a shank portion extending along the central axis, and an engaging portion which connects to the shank portion at a side of the first end and includes a diameter greater than the shank portion. The engaging portion is located in the recess.

A milling tool includes a tool head and an exchangeable cutter carrier. The tool head can be coupled to a tool holder, and the cutter carrier includes a plurality of cutters distributed around its circumference, each having a front facing face cutter and a peripheral cutter extending at an angle thereto. In this case, the cutter carrier, including the cutters, has a thickness of at most ten mm, in particular at most six mm, for a diameter of at least fifty mm.

A side milling cutter includes a main body extending along an axis from a first end with an interface for connection to a rotational drive to a free second end, receiving a bearing face for a disc-shaped cutter holder. The cutter holder is fastened to the second end and supported with a first main surface, facing the main body, on the bearing face, having an outer circumference projecting radially from the main body and a central through opening penetrating the cutter holder axially. Coolant feed channels feeding coolant to the second end are in the main body. Coolant distributing channels feeding coolant to the outer circumference of the cutter holder are in the cutter holder. At least two coolant distributing channels branch off from a common coolant distributing chamber between the main body and the cutter holder and into which at least two of the coolant feed channels open.

A rotary cutting tool has an insert receiving pocket with a cutting insert removably secured therein and an adjustment recess rearward thereof having a radially outward facing recess side surface and an adjustment tongue spaced apart therefrom by a first inner passage. The adjustment tongue extends rearwardly from a tongue root to a tongue tip and includes a tongue through bore. The tongue root has a shoulder surface facing in the forward direction and the cutting insert is in contact with the shoulder surface. An adjustment screw extends through the tongue through bore and engages the recess side surface, and rotation of the adjustment screw causes axial displacement of the cutting insert in a forward direction. An imaginary straight line in the first inner passage intersects a recess rear end surface formed on a first body sub-portion of the cutting body which is integrally formed with the adjustment tongue.

A rotary cutting tool has an insert receiving pocket with a cutting insert removably secured therein and an adjustment recess rearward thereof having a radially outward facing recess side surface and an adjustment tongue spaced apart therefrom by a first inner passage. The adjustment tongue extends rearwardly from a tongue root to a tongue tip and includes a tongue through bore. The tongue root has a shoulder surface facing in the forward direction and the cutting insert is in contact with the shoulder surface. An adjustment screw extends through the tongue through bore and engages the recess side surface, and rotation of the adjustment screw causes axial displacement of the cutting insert in a forward direction. An imaginary straight line in the first inner passage intersects a recess rear end surface formed on a first body sub-portion of the cutting body which is integrally formed with the adjustment tongue.

A modular cutting tool includes a cutting head, a shank and a mechanism which assists in assembling and locks the cutting head to the shank. The cutting head includes a cutting portion rotatable about a central longitudinal axis and a cylindrical skirt extending axially from the cutting portion and terminating at a contact face disposed perpendicular to the longitudinal axis. The skirt has a number of curved inner surfaces which generally define a bore disposed about the longitudinal axis. The shank includes a cylindrical portion of a first diameter disposed about the central longitudinal axis and a central protrusion disposed in the bore of the cutting portion. The central protrusion has a second diameter less than the first diameter and extends longitudinally from a contact face disposed perpendicular to the longitudinal axis at a leading end of the cylindrical portion.

A combined structure of an arbor and an arbor seat, including: an arbor, having a first assembling portion which has at least one first hole, each first hole having a first central axis; an arbor seat, having a second assembling portion which is disposed in the axial direction, and the first assembling portion and the second assembling portion being insertably connected with each other, the second assembling portion having at least one second hole which has a second central axis, when the first and second assembling portions are connected with each other in the axial direction, each second central axis is noncoaxial and nonoverlapped with the at least one first central axis; and wherein at least one said fastener is inserted into one said first hole and one said second hole, and urges one said first hole and one said second hole in axially opposite directions.