A rotary tool may include a body extending from a front end toward a rear end. The body may include a tip cutting edge, a corner cutting edge, an outer peripheral cutting edge, a first rake surface, a second rake surface, and a third rake surface. The corner cutting edge may extend from the tip cutting edge toward an outer periphery. The outer peripheral cutting edge may extend from the corner cutting edge toward the rear end. The first rake surface may be located along the tip cutting edge. The second rake surface may be located along the corner cutting edge. The first rake surface may have a straight line shape in a cross section orthogonal to the tip cutting edge, and the second rake surface may have a concave shape in a cross section orthogonal to the corner cutting edge.

An end mill, preferably made of solid carbide, with a fastening section and a cutting area, in which the cutting area is formed by a core and three or four cutting edges running helically around the axis of rotation of the end mill and arranged around core; each of which has a peripheral main cutting edge and a secondary cutting edge on a face of the cutting area. On the face of the cutting area at least one point thinning of core is provided between two adjacent cutting edges. In order to create end mills that are simple to manufacture and optimized for drilling, the point thinning has an angle of 30 to 40 relative to the axis of rotation of the end mill.

A cutting insert has top and bottom surfaces opposing each other and a side surface connecting them. A part of an intersecting ridge between the top and side surfaces functions as a cutting edge. On the side surface, a side surface portion adjacent to the intersecting ridge portion opposing the cutting edge intersects the top surface at an acute angle. At least on a part of a bottom surface, an inclined surface gradually approaching the top surface with increasing distance from a side surface portion on a side opposite to a cutting edge is formed. This allows a part of the cutting resistance to act on the side surface portion. As a result, friction resistance between the side surface portion and the side surface of an insert seat becomes larger, thereby suppressing a shifting of the cutting insert when cutting.

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 minor cutting edge has a first minor cutting edge and a second minor cutting edge that extends inward of the insert in a direction of an insert short side face axial line, as the second minor cutting edge extends from the first minor cutting edge in a direction of an insert major face axial line. A flank face of the second minor cutting edge is inclined outward of the insert in the direction of the insert short side face axial line, as the flank face extends from the second minor cutting edge in the direction of an insert long side face axial line, and is inclined outward of the insert in the direction of the insert short side face axial line, as the flank face extends from a major face adjacent to the flank face in the direction of the insert major face axial line.

In a roughing end mill, an end mill main body is provided with: a peripheral cutting edge; an end cutting edge; and a corner cutting edge formed between the peripheral cutting edge and the end cutting edge. A roughing part having a waveform pattern of recesses and protrusions is formed in the peripheral cutting edge, and a phase of the recesses and protrusions of the roughing part of one chip discharge flute is shifted with respect to that of the other chip discharge flute adjacent to the one chip discharge flute. A foremost protrusion of the roughing part of one peripheral cutting edge is located closer to a distal end of the end mill main body than those of the other peripheral cutting edges, a peak of the foremost protrusion of the one peripheral cutting edge is aligned with another peak of the corner cutting edge adjacent to the one peripheral cutting edge. Also, a peak of a foremost protrusion of the roughing part of each of the other peripheral cutting edges is connected to another peak of the corner cutting edge adjacent to the other peripheral cutting edge by another straight portion extending in a linear manner.

A multi-flute ball end mill comprising a shank portion, a cutting edge portion having a ball-shaped tip portion, and 3 or more cutting edges formed in the cutting edge portion; each cutting edge being constituted by a peripheral cutting edge having a twist angle of 35-45, and a ball-end cutting edge having a twist angle at the outermost peripheral point, the twist angle and the twist angle meeting the relation of 7, such that the ball-end cutting edge is smoothly connected to the peripheral cutting edge; the ball-end cutting edge having a radial rake angle of 37 to 11; the peripheral cutting edge having a radial rake angle of 2-8; and a center-lowered, inclined cutting edge integrally extending from a tip end of each ball-end cutting edge to a rotation center point, in a tip end portion of the ball portion near the rotation center point.

A radius end mill includes a corner R cutting edge which extends between the end cutting edge and the outer peripheral cutting edge; and a corner gash disposed adjacent to the corner R cutting edge of the rake face, wherein the corner gash in a planar shape has an edge, part of which is located at the center portion of the corner R cutting edge, and an axial rake at an end portion on the side of the end cutting edge which is in contact with the corner gash on the corner R cutting edge is in the range of 5 to 20 degrees.

A dental milling tool and corresponding method is provided. The dental milling tool includes a ball head portion which is rounded in a semispherical manner and which, at its largest outer diameter, approximately 1-4 mm, transitions into an axial cutting portion that runs in the axial direction with said diameter at the outer circumference in a constant manner, the axial cutting portion being adjoined by a shaft portion which extends axially with a larger or at least equally large shaft diameter. A milling method for producing dental prosthesis parts is provided wherein a dental prosthesis white body which is to be sintered into the completed dental prosthesis part is milled out of a pre-sintered ceramic white body, in particular a zirconium dioxide white body, on a multi-axis CNC milling machine with a milling tool according to one of the preceding claims using 3D freeform milling process along generated travel paths.

An end mill, preferably made of solid carbide, with a fastening section and a cutting area, in which the cutting area is formed by a core and three, four or five cutting edges arranged around core and running helically around the axis of rotation of the end mill, each one of which has a peripheral main cutting edge and a secondary cutting edge on the face of cutting area. In order to create an end mill simple to manufacture and optimized for drilling, at least one cutting edge on the face of cutting area has a single, flat or continuously curved front surface, which delimits the cutting edge in the longitudinal direction of the mill on face.