A hard coating, which is to disposed to cover a surface of a tool substrate, has a total thickness of 0.5-20 m and includes an A layer and nanolayer-alternated layer that are alternately laminated by physical vapor deposition. The nanolayer-alternated layer includes a B layer and C layer that are alternately laminated. The A layer has a thickness of 50-1000 nm and is AlCr(SiC) nitride that is represented by a composition formula of [Al.sub.1-W-XCr.sub.W(SiC).sub.X]N wherein an atomic ratio W is 0.20-0.80 and an atomic ratio X is 0.01-0.20. The B layer has a thickness of 1-100 nm and is TiAl nitride that is represented by a composition formula of [Ti.sub.1-YAl.sub.Y]N wherein an atomic ratio Y is 0.30-0.85. The C layer has a thickness of 1-100 nm and is Ti(SiC) nitride represented by a composition formula of [Ti.sub.1-Z(SiC).sub.Z]N wherein an atomic ratio Z is 0.05-0.45. The nanolayer-alternated layer has a thickness of 50-1000 nm.

A hard coating includes a thin film layer which has a total thickness of 0.5-10 m and has an overall composition of Al.sub.1-a-bTi.sub.aMe.sub.bN (0.2<a0.6, 0<b0.15) , where Me is a nitride constituent element having a thermal expansion coefficient of greater than 2.710.sup.6/ C. and less than 9.3510.sup.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.

A surface-coated cutting tool includes a base material and a coating formed on the base material. The coating includes an -Al.sub.2O.sub.3 layer. The -Al.sub.2O.sub.3 layer contains -Al.sub.2O.sub.3 crystal grains and sulfur, and has a TC(006) of more than 5 in texture coefficient TC(hkl). The sulfur has a concentration distribution in which a concentration of the sulfur decreases in a direction away from a base-material-side surface of the -Al.sub.2O.sub.3 layer, in a thickness direction of the -Al.sub.2O.sub.3 layer.

A cutting tool based on an embodiment of the present invention is provided with a cylindrical main body section which is made of a cobalt-containing cemented carbide alloy and is rotatable about the central axis thereof, a cutting edge which is provided at at least one of the tip and the periphery of the main body section, a chip discharge groove which extends from the cutting edge toward the rear end of the main body section, and a coating layer which is made of diamond and covers the cutting edge, wherein the cobalt content of the surface of the main body section at the part coated with the coating layer is less than the cobalt content of the surface of the main body section at parts other than the part coated with the coating layer.

A compound fillet radii cutter may have a shaft having a cylindrical member, frustoconical cutting surface, a small radius cutting surface having an arc length of a first circle, and a large radius cutting surface having an arc length of a second circle. The frustoconical cutting surface may be disposed between the cylindrical member and the small radius cutting surface. The small radius cutting surface may be disposed between the frustoconical cutting surface and the large radius cutting surface, and a juncture of the large radius cutting surface and the small radius cutting surface may form a tangential union. In this manner, a single cutter may cut radii of various sizes or cut compound radii.

A coated cutting tool and a hard and wear resistant coating for a body include at least one metal based nitride layer. The layer is (ZrxCrl-x-y-zAlyMez)Na with 0.55<x<0.85, 0.05<y<0.45, 0z<0.20, 0.95<a<1.10, and Me is one or more of the elements: Y, Ti, V, Nb, Ta, Mo, W, Mn or Si. The layer can have a thickness between 0.5 m and 15 m and be comprisied of a single cubic phase or a single hexagonal phase or a mixture thereof. In an exemplary embodiment, the layer is a cubic phase of a sodium chloride structure. The layer can be deposited using cathodic arc evaporation and is useful for metal cutting applications generating high temperatures.

A coated tool has a hard coating layer including a layer of a complex nitride or complex carbonitride expressed by (Ti.sub.1-xAl.sub.x)(C.sub.yN.sub.1-y). A periodic concentration variation is present in crystal grains of a complex nitride or complex carbonitride having a NaCl type face-centered cubic structure in the layer. The periodic concentration variation direction includes a direction at 30 degrees or less with respect to a surface of a tool body. An area percentage of a periodic concentration variation of Ti and Al is 40% or more. The concentration variation period is 1 to 10 nm. A difference between an average of local maximums and an average of local minimums of a periodically varying amount x of Al is 0.01 to 0.1. Fine crystal grains having a hexagonal structure with an average grain size of 0.01 to 0.3 m are present at grain boundaries in 5% or less of the area.

The present invention is an end-mill (A) comprising a shank (B) and a cutting portion (C) along its longitudinal axis (4), and formed by combining ceramic and metal based materials via brazing method, comprising: a cutting diameter (1) varying between 2 to 20 mm, at least one web thickness (18) 0 found at a blade (26) part, at least one helix angle (10) having a cutting edge (13) thereon, a core diameter (16) that is at least 0.7 times the cutting diameter (1), at least one corner radius (5) found at the tip part of the blades (26) between the flutes (9) and axial and radial rake angles (17) at which cutting operation is made. TiAlN coating is applied over ceramic-metal based 5 end-mill (A) by PVD method in order to extend the service life of the end-mill, increase abrasion resistance, and minimize the welding (sticking) problem of chips on the cutting tools.

The invention is a monolithic end-mill cutter set (A) that can be made of ceramic and/or other materials having high strength and toughness and comprising a shank part (B) along a longitudinal axis (4) and a cutter part (C), comprising: a cutting diameter (1) varying between 2 to 20 mm, at least one web thickness (18) found at a blade (26) part, at least one helix angle (10) having a cutting edge (13) thereon, a core diameter (16) that is at least 0.7 times the cutting diameter (1), at least one corner radius (5) found at the tip part of the blades (26) between the flutes (9) and axial and positive radial rake angles (17) at which cutting operation is made. It has a wide helix angle interval and a positive rake angle. Titanium Aluminium Nitride TiAlN coating can be made on the monolithic end-mill cutter set (A) via PVD coating method in order to extend the service life of the end-mill cutter set (A), increase the abrasion resistance, and minimize the problem of sticking of rake on the cutter set (joining).

A surface-coated tool includes a substrate and a coating film formed on the substrate. The coating film includes an alternate layer in which one or more A layers and one or more B layers are alternately stacked. The A layer and the B layer each have a thickness not smaller than 2 nm and not greater than 100 nm. An average composition of the A layer is expressed as TiaAlbSicN (0.5<a<0.8, 0.2<b<0.4, 0.01<c<0.1, a+b+c=1), an average composition of the B layer is expressed as TidAleSifN (0.4<d<0.6, 0.3<e<0.7, 0.01<f<0.1, d+e+f=1), and a condition of 0.05<AD0.2 AND 0.05<EB0.2 is satisfied.