A rotary cutting tool has a cutting tool body with a cutting end and a cutting portion adjacent to the cutting end. The cutting portion includes a first blade, which has a first finishing cutting portion and a first roughing cutting portion adjacent to the first finishing cutting portion. The cutting portion includes a second blade, which has a second finishing cutting portion and a second roughing cutting portion adjacent to the second finishing cutting portion. The first finishing cutting portion overlaps one or both of the second finishing cutting portion and the second roughing cutting portion. The first roughing cutting portion overlaps one or both of the second roughing cutting portion and the second finishing 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 (TiAlN), aluminium titanium nitride, (AlTiN), and titanium nitride (TiN), and ceramic coating.

An end mill includes a bar-shaped body, a cutting edge, a gash, a first flute, and a second flute. The body extends from a first end to a second end along a rotation axis. The cutting edge is located at a side of the first end of the body. The gash is located adjacent to the cutting edge. The first flute surrounds the gash and spirally extends from the gash toward the second end. The second flute surrounds the first flute and spirally extends from the first flute toward the second end. A depth of the first flute is greater than a depth of the second flute in a cross section orthogonal to the rotation axis.

A rotary cutting tool includes a shaft having and outer surface and having a longitudinal axis, a plurality of helical flutes formed in the shaft about the longitudinal axis, a plurality of helical cutting edges formed at an interface with the outer surface and a respective helical flute about the longitudinal axis, and a plurality of end cutting edges located on an axial distal end of a cutting portion of the shaft, the end cutting edges being contiguous with a corresponding one of the plurality of helical cutting edges and forming a corner in the transition between each of the end cutting edges and the corresponding one of the plurality of helical cutting edges. A hone edge extends along a portion of each of the end cutting edges, the associated corner and a portion of the corresponding one of the plurality of helical cutting edges.

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.

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 milling cutter includes a cutting section extending from a shank along an axis. The shank includes a free end as a first end of the milling cutter. The cutting section includes a free end as a second end of the milling cutter. The cutting section includes at least one right-hand cutting unit, at least one left-hand cutting unit and at least two grooves about the axis. Each of the grooves is made between the right-hand cutting unit and the left-hand cutting unit. The right-hand cutting unit includes several right-hand blades extending at a first helical angle relative to the axis. The left-hand cutting unit includes several left-hand blades extending at a second helical angle relative to the axis.

In a formed end mill, a peripheral cutting edge has a smaller-diameter cutting part and a larger-diameter cutting part. An imaginary line obtained by lining up a deepest point of a flute bottom of a chip discharge flute, which appears in a cross-sectional view perpendicular to an axis of an end mill body, in an extending direction of the chip discharge flute is defined as a virtual flute bottom line. A flute helix angle, which is formed between the virtual flute bottom line and the axis, in a side view when the end mill body is seen from a radial direction orthogonal to the axis, is 0 degrees or more at a distal end part of the chip discharge flute in the axial direction, and increases gradually from the distal end part toward a posterior end in the axial direction.

A rotatable cutting tool includes an elongate body having a longitudinal axis, a proximal end and a distal end 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.