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 (TiAlN), aluminium titanium nitride, (AlTiN), and titanium nitride (TiN), and ceramic coating.

A burr includes a shaft portion and a milling portion. Cutters are separated by main flutes having a main flute depth. The cutters extend helically at a first twist angle. Each cutter has a cutting edge between a rake face and a relief face. The rake face forms a rake angle, and the relief face forms a relief angle. Chip breakers in each relief face have a chip breaker depth. At the largest diameter of the milling portion, the chip breaker depth is between 5 and 25 percent of the main flute depth, the rake angle is between −3 degrees and +14 degrees, the relief angle is between 10 degrees and 20 degrees, the first twist angle is greater than 25 degrees, and the number of main flutes is less than 15.

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.

Chip breaking features may be arranged in radial reliefs of a rotary cutting tool. The chip breaking features create gaps or voids in the otherwise continuous cutting edge, resulting in otherwise continuous chips being cut into discrete chips. The chip breaking features may be angled so as to define a secondary cutting edge. Depending on the angle at which the chip breaking features are angled, the secondary cutting edges may partially or completely close the gaps or voids in the cutting edge. Closing the gaps or voids in the cutting edge ensures that each blade removes nearly all material so the following blade does not have to clean up.

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 (TiAlN), aluminium titanium nitride, (AlTiN), and titanium nitride (TiN), and ceramic coating.

The invention relates to an apparatus for processing cylinder walls of internal combustion engines (1), including a cutting element (4). The cutting element (4) is arranged on a rotary cutting ring (3). The cutting element (4) has a slit contour (5) with a plurality of cutting edges (6) arranged next to each other in a direction of an axis of rotation of the rotary cutting ring. And, the individual cutting edges (6) face in a direction of rotation of the rotary cutting ring.

A rotary cutting tool. The tool has 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 () 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. Large core diameters of cutting tools are provided, which gives high strength when working with axial depths of cut of about three times outside tool diameter or less.

A rotatable cutting tool includes an elongate body and at least one helical flute extending over a length of the elongate body, the helical flute having a first end and a second end. The flute includes a cutting-edge with a first radius from a longitudinal center of the cutting tool, a trailing edge with a second radius from a longitudinal center of the cutting tool, wherein the second radius is smaller than the first radius, a flute surface between the cutting-edge and the trailing edge, the flute surface including a maximum radius at the cutting-edge and a plurality of foam chip shedding exclusions spaced along the cutting-edge of the helical flute, each of the foam chip shedding exclusions providing a gap in the cutting-edge where the radius within the gap is smaller than the first radius. The first radius defines a maximum tool cutting radius for the cutting tool. A gap distance between the foam chip shedding exclusions and the maximum tool cutting radius equals at least 15% of a radial height of the flute.

A method for the laser-based generation of a structure on a rake face of a cutting tool is disclosed, where at least one structure is formed by lines that are generated with a mutual spacing of at most 400 m with a laser beam at least in areas within a predetermined contour on at least one rake face of the cutting tool. A course of the lines forming the structure is oriented with respect to a profile of at least one cutting edge of the at least one rake face.