A milling tool having a front end, a rear end, a longitudinal axis extending therebetween, a shank portion and a cutting portion. The cutting portion includes a plurality of teeth separated by a corresponding number of flutes. Each tooth extends axially along the cutting portion following a curved helical path around the longitudinal axis, and extends at a first helix angle from the front end to a helix transition, and at a second helix angle from the helix transition towards the shank portion. The second helix angle is greater than the first helix angle by at least 2° and at most 15°. The first helix angle (α) is 33°≤α≤50°, and the second helix angle (β) is 40°≤β≤55°, and wherein the helix transition is axially located from the front end by 0.2 to 0.7 of the longitudinal length of the cutting portion.

Rotary cutting tool (100) having plurality of major flutes (130) arranged helically opposite to plurality of discontinuous minor flutes (135) and intersecting to form plurality of teeth. Each tooth includes a first cutting edge formed with the major flute and a second cutting edge formed with the minor flute, the first and second cutting edges meeting at an apex and form part of a periphery of a quadrilateral-shaped face portion. The face portion has non-planar surfaces extending from the respective first and second cutting edges that define a relief surface of each cutting edge. First and second cutting edges are arranged on an imaginary cylinder having a center axis coaxial with the axis of rotation of the tool and respective relief surfaces are radially inward of a surface of the imaginary cylinder such that the first and second cutting edges each have a clearance in a rotational direction of the tool.

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 rotary tool may include a main body having a circular columnar body, including a rotation axis and extending from a first end to a second end. The main body may include first flutes, second flutes, a first cutting edge, and a second cutting edge. The first flutes may have a helix angle θ1 and the second flutes a reverse helix angle θ2. The first cutting edge may be located on a ridge line where the outer periphery of the main body intersects with the first flutes and the second cutting edge at a ridge line where the outer periphery of the main body intersects with the second flutes. The θ2 may be larger than the θ1, m≥5, m−n≥3, and m and n are coprime numbers, where m is the number of the first flutes and n is the number of the second flutes.

A end mill includes: an end mill body having a rotation axis, the end mill body including a shank portion and a cutting portion with an outer peripheral cutting edge; an end cutting edge including a first cutting edge and a second cutting edge; a first gash opening between the first cutting edge and the second cutting edge; and a second gash located adjacently to the first gash in the rotational direction, and opening to a side closer to the outside peripheral from the chisel portion. A ratio (L1/L2) of a length (L1) from a distal end of the end mill body to a terminal end of the first gash to a length (L2) from the distal end of the end mill body to a terminal end of the second gash, when viewed from a side, is from 0.8 to 1.1.

An end mill includes end cutting edges located at a front end side of a cutting edge portion of a body including rotation axis, peripheral cutting edges, and helically extending flutes. Each of the peripheral cutting edges and the flutes are alternately located from the front end side to a rear end side, and a first distance between a deepest position of the flute and the rotation axis is equal among the respective flutes in a cross section taken along the rotation axis. The flute includes a first region located at a side of the peripheral cutting edge and includes the deepest position, a second region located at a side of a heel, and a boundary. A second distance from the rotation axis to the boundary located at the rear end side is larger than the second distance located at the front end side.

A milling tool for milling workpieces, having a shank which can be rotated about an axis of rotation and at least one milling portion arranged on the shank along the axis of rotation. The milling portion first and second cutters arranged on the circumference and extending substantially over the milling portion in the direction of the axis of rotation and next to one another and/or one behind another as viewed in the direction of rotation/circumferential direction. The first cutter is arranged at a first angle and the second cutter is arranged at a second angle with respect to the axis of rotation. The first angle is not equal to the second angle. A first chip receptacle for receiving a chip of the workpiece that has been cut off is arranged at least between the first and the second cutter.

Rotatable, solid cutting tool with both right-hand spirals and left-hand spirals, each of which includes an interrupted cutting edge having individual cutting edges. Individual cutting edges of the right hand spirals are axially staggered helically around a circumference of a cutting portion with respect to individual cutting edges of the left hand spirals so that, at each axial position along an axial length of the cutting portion, each radial cross-section includes both at least one individual cutting edge on a right hand spiral and at least one individual cutting edge on a left hand spiral. Individual cutting edges have a length along an outer circumference of the cutting tool that is the same for individual cutting edges of the right hand spiral and individual cutting edges of the left hand spirals. Cutting edges on differently handed spirals are both right handed cutting edges or both left handed cutting edges.

A corner radius end mill includes a blended gash extending along a cutting edge. The blended gash is formed in a corner sector of the end mill. The corner sector has a first half-sector and a second half-sector defined on opposite sides of an imaginary bisection line of the corner sector, the first and second half-sectors subtending equal angles about the imaginary bisection line. The blended gash extends from a first extremity and blends an end gash surface and flute rake surface of the corner radius end mill. The blended gash is spaced from a radial tangent point by a predetermined distance, and extends to a second extremity which is spaced apart from the axial line and the second half-sector.

In an aspect, a rotating tool includes a main body having a rod shape and extending along a rotation axis. The main body includes a first end, a second end, a twisted cutting edge located at a side of the first end, a twisted flute, a reverse twisted cutting edge located closer to the second end than the twisted cutting edge, and a reverse twisted flute. The reverse twisted flute is connected to the twisted flute. The twisted cutting edge includes a first part having a length from the rotation axis decreasing as approaching toward the second end.