A shaft portion and a blade portion provided on a side surface of the shaft portion are included, and the blade portion includes cutting blades arranged in a plurality of lines on a side surface of the shaft portion along a peripheral direction, and arranged in a plurality of stages in an extending direction of a shaft center of the shaft portion in each line. Further, the cutting blade has a radial-direction clearance angle, a tip end-side clearance angle, and a base end-side clearance angle.

Novel endmills are provided. Such endmills have a body with outside diameter (OD), and outer surface, and a longitudinal axis, a plurality of flutes, helical in some embodiments. Flutes include a narrow leading edge land portion with circular segment profile and having flute cutting edge portions along a substantially uniform circumferential location, with an eccentric relief margin rotationally rearward of the narrow leading edge land portions. Face portions are provided with face cutting edge portions, and with a first dish portion adjacent each of the cutting edge portions sloping inwardly and downwardly generally toward a central longitudinal axis at a first dish angle alpha (α). Corner blend portions extend from flute cutting edge portions to the face cutting edge portions. Corner blend portions are provided in a variety of profiles, including an embodiment wherein the profile of the corner blend portions are truncated before the segment of curvature becomes tangential to the face cutting edge portions. In various embodiments, one or more coolant passageways are provided, and in an embodiment, an exit port for coolant is provided at the center of rotation of the end face portion.

The invention provides a dental milling tool for milling dental materials in the making of dental prostheses. The dental milling tool is a ball-nose end mill having three helical flutes, each flute being associated with a cutting edge, each cutting edge having chip breakers along the curved edges of the ball. The dental milling tool may be formed from a hard material such as carbide based material, ceramic, cermet, superhard materials including polycrystalline diamond (PCD) and cubic boron nitride (CBN), and diamond composite. Alternatively, the dental milling tool may be coated with a hard coating such as diamond coating, diamond-like-carbon (DLC), nitride based coating such as titanium aluminium nitride (TiAIN), aluminium titanium nitride, (AITiN), and titanium nitride (TiN), and ceramic coating.

A cutter head structure includes a cutting edge portion including a cutting body. An outer surface of the cutting body is a curved surface which protrudes forwardly. The outer surface of the cutting body is provided with a first cutting edge and at least two second cutting edges. The first cutting edge extends from one side of the cutting body to a top region of the cutting body and then to the other side of the cutting body. The second cutting edges are respectively disposed on both sides of the first cutting edge. First chip flutes are defined between the first cutting edge and the second cutting edges adjacent thereto, and each of the first chip flutes has a width gradually increasing from the top region to both ends of the cutting body.

A ceramic tool with integrated temperature sensing and cutting functions and preparation method and application thereof. The ceramic tool comprises a ceramic matrix, a positive thermoelectric layer and a negative thermoelectric layer being provided on two surfaces of the ceramic matrix; the ceramic matrix being formed by sintering a first matrix material, a first binding agent and a first reinforcing phase, and the thermoelectric layer being formed by sintering of a thermoelectric material; the first matrix material comprises one or more of Al.sub.2O.sub.3, Si.sub.3N.sub.4 and CBN; the first binding agent comprises one or more of Mo, Ni, Co, W and Cr; the first reinforcing phase comprises one or more of TiC, WC, SiC, MgO, Cr.sub.2O.sub.3, TiO.sub.2 and ZrO.sub.2; the thermoelectric material for the positive thermoelectric layer comprises ZrB.sub.2 and SiC; the thermoelectric material for the negative thermoelectric layer comprises ZrB.sub.2, SiC, and graphite.

A method for producing a coated cutting tool for metal machining having a substrate and coating is provided. The coating includes at least one layer of (Ti,Al)N having a cubic crystal phase. The method includes the deposition of a layer of Ti.sub.1-xAl.sub.xN, 0.70≤x≤0.98, the Ti.sub.1-xAl.sub.xN having cubic crystal phase. The layer of Ti.sub.1-xAl.sub.xN is deposited by cathodic arc evaporation at a vacuum chamber pressure of from 7 to 15 Pa of N.sub.2 gas, using a DC bias voltage of from −200 to −400 V and using an arc discharge current of from 75 to 250 A. A coated cutting tool for metal machining having a coating including a (Ti,Al)N multi-layer of alternating sub-layers of at least Ti.sub.1-yAl.sub.yN and Ti.sub.1-zAl.sub.zN, 0.35≤y≤0.65 and 0.80≤z≤0.98, with only cubic phase present is also provided.

An end-mill comprising a shank and a cutting portion along its longitudinal axis, and formed by combining ceramic and metal based materials via a brazing method. The cutting portion includes a cutting diameter varying between 2 to 20 mm, at least one web thickness found at a blade part, at least one helix angle having a cutting edge thereon, a core diameter that is at least 0.7 times the cutting diameter, at least one corner radius found at the tip part of the blades between the flutes, and axial and radial rake angles at which a cutting operation is made. TiAlN coating is applied over the ceramic-metal based end-mill by a 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.

A cutting tool, including a silicon nitride (Si.sub.3N.sub.4) ceramic substrate, and a diamond film coated on the surface of the Si.sub.3N.sub.4 ceramic substrate. The diamond film has a thickness of 7-12 μm. The cutting tool includes a tool nose, a blade, and a handle. The blade has a rake angle γ of 5-15°, a clearance angle α of 10-14°, and a helix angle of 15-45°. The blade includes four cutting edges.

A cutting machine includes a holder located below a spindle to hold processing targets, and an adaptor connected to a rotation shaft to rotatably support the holder. The holder includes a first holder fixed to the adaptor and including a pin insertion hole to which a fixing pin attached to a processing target is fixed, and a second holder detachably attached to the first holder and including a pin insertion hole at a position facing the pin insertion hole. The fixing pin extends in a Y-axis direction. In the Y-axis direction, a distance between a processing target fixed to the pin insertion hole and a processing target fixed to the pin insertion hole is shorter than a length of the fixing pin.

In an end mill body made of ceramic, a corner R rake face is formed in such a manner as to contain a point B and at least a region B, not a region A located on a side toward an end cutting edge. In other words, a first end portion of a cutting edge on a peripheral edge portion of the corner R rake face is formed on a peripheral edge of the region B of a corner R cutting edge, and a second end portion of the cutting edge reaches at least the point B. As a result, partial breakage of the corner R cutting edge is unlikely to occur in the course of cutting. That is, since the corner R rake face is formed in such a manner as to start from the first end portion located apart from a point A, which is the intersection of the end cutting edge and the corner R cutting edge, and such that the second end portion reaches the point B, a large cutting load is unlikely to be imposed on the starting point of the corner R rake face. Therefore, the corner R cutting edge is unlikely to be chipped.