Abstract: The present invention relates to a cutting insert. The cutting insert, according to one embodiment of the present invention, comprises: a top surface; a bottom surface; side surfaces which connect the top surface and the bottom surface to each other; a hole which penetrates the top surface and the bottom surface; and cutting edges which are defined by the top surface and the side surfaces, wherein a main cutting edge side surface among the side surfaces is provided with a first relief surface, a transition surface extending from the first relief surface, and a second relief surface extending from the transition surface, the first relief surface is formed such that the relief angle or the relief surface width varies along the cutting edge, and the transition surface is provided with a plurality of ridges in order to reinforce the rigidity of the cutting edge.

Abstract: A technical object is to provide an apparatus for attaching or detaching an insert of a cutting tool, which enables easy and fast replacement of the insert. To this end, the apparatus for attaching or detaching the insert to or from a body of the cutting tool is provided in the body of the insert and includes an insert receiving portion formed in the body of the cutting tool to receive the insert therein, a wedge receiving portion formed in the body of the cutting tool continuously after the insert receiving portion, a wedge received in the wedge receiving portion, and a rotating unit configured to rotate the wedge in a first direction that faces the insert receiving portion, or to a second direction opposite the first direction.

Abstract: The present invention relates to a cutting tool, which performs, like a drill or a ball end mill, cutting while rotating in a state in which the center of the tip end is in contact with a work material, and includes a wear-resistant layer formed at the tip end thereof, wherein a portion of the wear-resistant layer is selectively removed through tip end polishing from the center of the tip end of the drill or the ball end mill to a predetermined area, so as to restrain micro-brittle wear generated in an ultra-low speed region, and thus remarkably improving the cutting lifespan of the cutting tool such as the drill or the ball end mill.

Abstract: Disclosed is an alpha alumina (?-Al2O3) thin film comprising the lower layer formed on the base material made from cemented carbide; and the ?-Al2O3 thin film layer formed on the lower layer, wherein when the ?-Al2O3 thin film layer is divided, from the total thickness (T) thereof, into a D1 layer which is from an interface layer to 0.15T, a D2 layer which is from 0.15T to 0.4T, and a D3 layer which is from 0.4T to 1T, an S1 (D3 layer grain size/D1 layer grain size) is 2-5.5 and an S2 (D2 layer grain size/D1 layer grain size) is 1.5-4.

Abstract: A cutting insert for an indexable drill according to the present disclosure may be used for external cutting or internal cutting depending on a position and a direction in which the cutting insert is installed even though a single type of cutting insert is provided. In addition, the cutting insert for an indexable drill according to the present disclosure has a section of the internal cutting edge which is involved in a cutting process or a section of the internal cutting edge which is not involved in the cutting process, which are clearly distinguished from each other, and as a result, the cutting insert may be rotated and mounted, and reversed and mounted on a drill body, such that maximum eight corners may be used to perform a cutting process.

Abstract: A technical object is to provide an insert capable of preventing escaping of the insert from an assembly of the insert and a tool holder. To this purpose, the insert includes an insert body, and a holder fastening portion provided in the insert body to be fastened to the tool holder, in which the holder fastening portion includes one or more fastening holes formed through the insert body from an upper surface to a lower surface, and one or more locking holes formed by being recessed in a lower surface periphery of the insert body.

Abstract: A technical object of the present disclosure is to provide an insert, which can maintain rigidity thereof regardless of a clearance angle of a clearance surface that forms a circular cutting edge. To this end, the insert according to the present disclosure includes a circular upper surface, a circular lower surface, and a clearance surface portion connecting the upper surface and the lower surface. The clearance surface portion is divided into first and second clearance surfaces along a circumference thereof, by a first wave line that forms a waveform of valleys facing the lower surface and mounts facing the upper surface.

Abstract: The present disclosure relates to a cutting insert and an indexable drill. The cutting insert and the indexable drill according to the present disclosure are configured such that when the cutting insert is mounted on the indexable drill, the cutting insert is easily inserted into the indexable drill at the initial time, and strong coupling force is implemented between the indexable drill and the cutting insert at a point of time at which the cutting insert is completely mounted. In addition, the cutting insert, according to the present disclosure, has excellent rigidity, when compared to cutting inserts in the related art that perform identical/similar cutting processing, since a portion, which is weak in rigidity, is provided as a thick portion.

Abstract: Provided is a hard film for a cutting tool formed on a surface of a base material, the hard film being comprised of a nano multi-layered structure formed by sequentially stacking a thin layer A, a thin layer B, a thin layer C and a thin layer D or being comprised of a structure formed by repeatedly stacking the nano multi-layered structure at least twice, wherein the thin layer A is comprised of TixAl1-xN (0.5?x?0.7); the thin layer B is comprised of Al1-y-zTiyMezN (0.4?y?0.7, 0<z?0.1 where Me is at least one of Si, Cr, and Nb); the thin layer C is comprised of AlaTi1-aN (0.5?a?0.7); and the thin layer D is comprised of AlbCr1-bN (0.5?b?0.7).

Abstract: Provided is a hard film formed on a surface of a base material, the hard film being comprised of a nano multi-layered structure formed by stacking a thin layer A, a thin layer B a thin layer C in order of thin layers A-B-A-C from the base material or being comprised of a structure formed by repeatedly stacking the nano multi-layered structure at least twice, wherein the thin layer A is comprised of Ti1-xAlxN (0.3?x?0.7); the thin layer B is comprised of Al1-yCryN (0.3?y?0.7); and the thin layer C is comprised of MeN (where Me is any one of Nb, V, and Cr).

Abstract: Disclosed is a hard coating film formed on a hard base material such as cemented carbide. The hard coating film has a nanoscale multilayered structure to have improved oxidation resistance and wear resistance. The hard coating film is a hard coating film formed on the base material. The first layer is composed of a TiAl nitride having a composition of Ti1-aAla (0.3?a?0.7), and the second layer has a nanoscale multilayered structure or a structure in which the nanoscale multilayered structure is repeatedly laminated at least two times, the nanoscale multilayered structure including a thin layer A composed of an AlTiSi nitride, a thin layer B, a thin layer C composed of a AlCr nitride, and a thin layer D having thicknesses of 3 nm to 20 nm. The thin film B and the thin film D are composed of a TiAl nitride.

Abstract: Provided is a hard film for a cutting tool formed on a surface of a base material, the hard film being comprised of a nano multi-layered structure comprising a thin layer A, a thin layer B, a thin layer C and a thin layer D or a structure in which the nano multi-layered structure is repeatedly stacked at least twice, wherein the thin layer A is comprised of Ti1-xAlxN (0.5?x?0.7); the thin layer B is comprised of Al1-y-zTiyCrzN (0.3?y?0.6 and 0<z?0.3); the thin layer B is comprised of MeN (where Me is Nb or V); and the thin layer D is comprised of Al1-a-bTiaSibN (0.3?a?0.7 and 0<b<0.1).