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 recesses formed by being recessed in a lower surface periphery of the insert body.

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: The present invention relates to a hard coating including an MT-TiCN layer and an ?-alumina layer which are formed by using a chemical vapor deposition method. A hard coating for cutting tools, which is a coating formed on a base material of a cutting tool formed of a hard material, the coating comprising: a TiCN layer; and an ?-alumina layer formed on the TiCN layer, wherein: the ?-alumina layer has a main peak (maximal strength peak) of (006) plane located between 20-40 degrees during a psi rocking analysis by an XRD; a residual stress in the ?-Al2O3 layer is ?0.9-0.4 GPa; the TiCN layer is composed of TiCxNyOz (x+y+z?1, x>0, y>0, z?0); a composition ratio of C/(C+N) is greater than or equal to 0.4 and smaller than 0.5; the ratio of TC(220)/TC(422) is smaller than 0.45; and the ratio of TC(220)/TC(422) is less than 0.45.

Abstract: A hard coating includes a thin film layer which has a total thickness of 0.5-10 ?m and has an overall composition of Al1-a-bTiaMebN (0.2<a?0.6, 0<b?0.15) , where Me is a nitride constituent element having a thermal expansion coefficient of greater than 2.7×10?6/° C. and less than 9.35×10?6/° C., wherein the thin film layer has a structure in which a nano-multilayered-structure of thin layers A, B and C, thin layer B being disposed between thin layer A and thin layer C, is repeatedly laminated at least once.

Abstract: The purpose of the present invention is to provide a cutting insert capable of reducing cutting load and enhancing squareness.

Abstract: A cemented carbide comprises particles including a tungsten carbide (WC) as a main component; a binder phase including cobalt (Co) as a main component; and particles including a carbide or a carbonitride of at least one selected from the group consisting of Group 4a, 5a, and 6a elements, or a solid solution thereof, wherein a cubic phase free layer (CFL), in which the carbide or the carbonitride is not formed, is formed from a surface of the cemented carbide to a depth of 5 ?m to 50 ?m.

Abstract: A cutting tool comprises a base material which includes particles including a tungsten carbide (WC) as a main component, a binder phase including cobalt (Co) as a main component, and particles including a carbide or a carbonitride of at least one selected from the group consisting of Group 4a, 5a, and 6a elements, or a solid solution thereof; and a hard film formed on the base material, wherein the hard film comprises at least an alumina layer, a cubic phase free layer (CFL), in which the carbide or the carbonitride is not formed, is formed from a surface of the base material to a depth of 10 ?m to 50 ?m, and a Co content of a surface of the CFL is 80% or more of a maximum Co content of the CFL.

Abstract: Provided are a cutting insert and a tool holder on which the cutting insert is provided. The cutting insert includes a circular upper surface, a circular lower surface, a cylindrical lateral surface for connecting the upper surface and the lower surface, an upper cutting edge formed between the upper surface and the lateral surface, a lower cutting edge formed between the lower surface and the lateral surface, and a plurality of rotation-preventing parts provided at the lateral surface so as to prevent the cutting insert from rotating with respect to the tool holder. Each rotation preventing part includes an inner curved surface recessed toward the center of the lateral surface and convexly rounded so as to form concentric circles in conjunction with the lateral surface, and a stepped rotation-preventing surface parallel to the axial direction of the insert and connecting the inner curved surface and the lateral surface.

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: 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: 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: 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 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: 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).

Abstract: Provided is a multilayer thin film for a cutting tool, in which unit thin films each of which is formed of a total of four thin layers are stacked more than once, the multilayer thin film being capable of realizing improved physical properties compared with conventional one by adjusting an elastic period and a lattice period between the four thin layers. The multilayer thin film for a cutting tool according to the present disclosure is a multilayer thin film for a cutting tool, in which unit thin films each of which is sequentially stacked with thin layers A, B, C, and D are stacked more than once, wherein elastic modulus k between the thin layers satisfies relationships of kA, kC>kB, kD or kB, kD>kC, kA, and lattice parameter L between the thin layers satisfies relationships of LA>LB, LD>LC or LC>LB, LD>LA.

Abstract: Provided is a multilayer thin film for a cutting tool, in which micro-scale thin films having a thickness of a few nanometers to tens of nanometers are alternately stacked, having less quality variations and being capable of realizing excellent wear resistance. The multilayer thin film according to the present disclosure is a multilayer thin film for a cutting tool, in which unit thin films which are respectively formed of thin layers A, B, C, and D are stacked more than once, wherein elastic moduluses k of the thin layers satisfy relationships of kA>kB, kD>kC or kC>kB, kD>kA, lattice parameters L of the thin layers satisfy relationships of LA, LC>LB, LD or LB, LD>LA, LC, and a difference between maximum and minimum values of the lattice parameter L is 20% or less.