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.

An indexable cutting insert has upper and lower surfaces with a peripheral surface extending therebetween and having four side surfaces alternating with four corner surfaces. The side and corner surfaces intersect the upper surface to form side and corner cutting edges, respectively. Each side cutting edge includes a primary cutting edge adjoining one of the corner cutting edges at a first endpoint and a secondary cutting edge adjoining another one of the corner cutting edges at a second endpoint. In a top view, the four primary cutting edges define an imaginary first square, each primary cutting edge is tangential to its adjoining corner cutting edge, and each secondary cutting edge is curved and entirely located in one of four imaginary quadrants. The insert is removably secured in a rotary cutting tool such that one of the secondary cutting edges contains the axially forwardmost point of the insert's upper peripheral edge.

An indexable cutting insert has upper and lower surfaces with a peripheral surface extending therebetween and having four side surfaces alternating with four corner surfaces. The side and corner surfaces intersect the upper surface to form side and corner cutting edges, respectively. Each side cutting edge includes a primary cutting edge adjoining one of the corner cutting edges at a first endpoint and a secondary cutting edge adjoining another one of the corner cutting edges at a second endpoint. In a top view, the four primary cutting edges define an imaginary first square, each primary cutting edge is tangential to its adjoining corner cutting edge, and each secondary cutting edge is curved and entirely located in one of four imaginary quadrants. The insert is removably secured in a rotary cutting tool such that one of the secondary cutting edges contains the axially forwardmost point of the insert's upper peripheral edge.

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 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 machine tool includes: a column; a spindle head supported by the column; a spindle in the spindle head; a draw bar moved upward to clamp a tool to the lower end portion of the spindle and moved downward to release the tool therefrom; a biasing portion biasing the draw bar upward; a cam mechanism including a cam in the column and an arm whose one end slides on a cam surface such that the other end pushes down the draw bar; a measurement portion measuring the position of the draw bar; a storage portion storing a position relationship between the spindle head and the draw bar when the cam mechanism is normal; and an abnormality determination portion determining an abnormality in the cam mechanism based on the position of the draw bar measured with the measurement portion and the relationship stored in the storage portion.

A T-slot cutter (1) is a tool for cutting a T-groove in a workpiece, and includes a body (2A) and an insert portion (3). The insert portion (3) is fixed to a leading end portion of the body (2A) using screws (8). The insert portion (3) is configured by overlaying inserts (4) and (5). By changing a combination of the inserts configuring the insert portion (3), a groove width and an angular shape of the T-groove cut in the workpiece can be easily adjusted. On mating faces of the inserts (4, 5), convex portions and concave portions of the mating face of the insert (4) overlap with concave portions and convex portions of the mating face of the insert (5). As a result, the inserts (4, 5) partially overlap with each other in a thickness direction, and thus a protrusion length of the insert portion (3) can be shortened.

A T-slot cutter (1) is a tool for cutting a T-groove in a workpiece, and includes a body (2A) and an insert portion (3). The insert portion (3) is fixed to a leading end portion of the body (2A) using screws (8). The insert portion (3) is configured by overlaying inserts (4) and (5). By changing a combination of the inserts configuring the insert portion (3), a groove width and an angular shape of the T-groove cut in the workpiece can be easily adjusted. On mating faces of the inserts (4, 5), convex portions and concave portions of the mating face of the insert (4) overlap with concave portions and convex portions of the mating face of the insert (5). As a result, the inserts (4, 5) partially overlap with each other in a thickness direction, and thus a protrusion length of the insert portion (3) can be shortened.

The invention concerns a shrink-fit chuck (1) for clamping an object, in particular for clamping a milling cutter in a milling machine, having a cylindrical receiving bore (3) for receiving a cylindrical shank of the object to be clamped, the receiving bore (3) extending in the shrink-fit chuck (1) and being bounded on the outside by a wall (4). The shrink-fit chuck (1) according to the invention is characterised by a rib (12) which extends transversely to the longitudinal axis (13) of the receiving bore (3) and projects inwards from the wall (4) of the receiving bore (3) into the receiving bore (3), so that the rib (12) permits the complete insertion of the shank (5) into the receiving bore (3) only in a predetermined angular position of the shank (5).

An indexable cutting insert has upper and lower surfaces with a peripheral surface extending therebetween and having four side surfaces alternating with four corner surfaces. The side and corner surfaces intersect the upper surface to form side and corner cutting edges, respectively. Each side cutting edge includes a primary cutting edge adjoining one of the corner cutting edges at a first endpoint and a secondary cutting edge adjoining another one of the corner cutting edges at a second endpoint. In a top view, the four primary cutting edges define an imaginary first square, each primary cutting edge is tangential to its adjoining corner cutting edge, and each secondary cutting edge is curved and entirely located in one of four imaginary quadrants. The insert is removably secured in a rotary cutting tool such that one of the secondary cutting edges contains the axially forwardmost point of the insert's upper peripheral edge.