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.

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 a ring-shaped tool for processing a workpiece, wherein the tool has a fastening region which is centred with its ring shape for fastening to a rotatable drive shaft, wherein the tool has cutting teeth and the teeth extend on both sides of the tool in each case from the head region of the tool in the direction of the fastening region, the teeth on one side having a right-hand twist and providing right-hand cutting, and the teeth on the other side having a right-hand twist and providing left-hand cutting.

The invention concerns a machining tool for machining fiber-reinforced materials such as CFRP, glass-fiber-reinforced plastics or plastics reinforced with polyester threads. The machining tool comprises a plurality of flutes (1, 2, 3, 4) which distance lands (5, 6, 7, 8), disposed about a cylinder core segment (9), from each other in the peripheral sense. At least one of the lands (6, 8) is designed as a premachining land (6, 8) and at least one other of the lands (5, 7) is designed as a postmachining land (5, 7), each comprising a peripheral working region extending along, or with a twist and in the form of a helical segment about, the tool axis. The working region of each premachining land (6, 8) is designed as a peripheral file with a plurality of teeth (10) which are incorporated in a cylinder surface segment-shaped outer surface of the working region, and provided in the working region of each postmachining land (5, 7) is a number of sharp cutting edges (11, 12, 13, 15) extending parallel to or with a twist and in the form of a helical segment about the tool axis. The invention is characterized in that the number of sharp cutting edges (11, 12, 13, 15) on at least one postmachining land (5, 7) comprises a plurality of cutting edges (11, 12) each provided on a peripheral casing groove, the casing grooves being incorporated in a cylinder surface segment-shaped outer face of the working region, parallel to each other and at a pitch relative to the flute (1, 3) leading at least one postmachining land (5, 7).

The present invention includes an end mill body which is formed of ceramic, a chip discharge flute which is formed on an outer periphery of the end mill body, a peripheral cutting edge which is formed on an intersection ridge line between a wall surface facing a tool rotation direction in the chip discharge flute and an outer peripheral surface of the end mill body, an end cutting edge which is formed on an intersection ridge line between the wall surface in the chip discharge flute and a tip surface of the end mill body, and a corner cutting edge which is positioned at a tip outer-peripheral part of the end mill body, connects an outer end of the end cutting edge and a tip of the peripheral cutting edge to each other, and has a convexly curved shape which is convex toward a tip outer-peripheral side of the end mill body.

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.

A beveling cutter can include a body with a shaft hole formed through the center. The cutter can also include a plurality of 10 cutter blades arranged at predetermined distances on the circumferential surface of the body, each having a radial primary blade with a radial primary relief angle (a) ranging from about 5 to about 15 degrees and a radial secondary blade with a radial secondary relief angle (b) ranging from about 16 to about 30 degrees. The cutter can also include discharge grooves formed longitudinally between the cutter blades to discharge chips produced in beveling, and a key groove formed at a portion inside the body, in which the helix angle (d) of the cutter blades ranges from about 5 to about 45 degrees. With the beveling cutter, it is possible to smoothly discharge chips produced in beveling and to prevent damage to the cutter blades.

A helical blade cutter including multiple linear blades attached to an outer circumferential surface of a round body having an outer surface formed into a cylindrical circumferential surface. The blades tilt to a given helix angle α from a straight line on the outer circumferential surface parallel to a rotational central axis O. Blade attachment surfaces are formed on the outer circumferential surface of the round body at given intervals in the circumferential direction. The blade attachment surfaces tilt to an angle same as the helix angle α of the blade while tilting to a rake angle β in a direction of an elevation angle from a tangent to the outer circumferential surface. The blades are each attached to a blade attachment part through intervention of a chip holder that allows detachment of the blade.

A rotatable cutting tool for machining of a honeycomb core includes a front end; a rear end; a peripheral surface extending between the front and rear ends; a set of helical flutes formed in the peripheral surface at a first helix angle 45°≤α≤65°, having a first depth; and a set of helical ridges. At least one helical groove formed in the peripheral surface at a second helix angle 90°<β≤100°, has a second depth, which is smaller than the first depth. The at least one helical groove intersects the helical ridges so that a plurality of cutting teeth are formed on each helical ridge. Each cutting tooth includes a second ridge formed in a transition between two lands, a cutting edge and a clearance edge join in a tooth tip constituting the radially outermost point of the cutting tooth.

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.