A drill bit has a tool shank, a center axis, a first cutting region with at least one geometrically defined first cutting edge, the same having a cutting face arranged at a radial distance from the center axis of the drill bit. The first cutting edge forms a countersink angle with the center axis. The drill bit having a chip shaping stage functionally assigned to the first cutting edge formed by the cutting face of the first cutting edge and by a shoulder surface adjoining the cutting face and forming a shoulder angle with the same, wherein the shoulder angle is greater than 90°, and preferably greater than 100°. The cutting face runs at a radial rake angle with respect to an imaginary radial line which cuts the first cutting edge, the same functionally assigned to the cutting face. The radial rake angle is positive.

A drill according to an embodiment includes a bar-shaped drill body extending along a rotation axis, a cutting edge located at a front end of the drill body, and a first flute extending spirally from the cutting edge toward a rear end of the drill body. The first flute includes a first region which is located close to the front end and has a helix angle θ1, and a second region which is located closer to the rear end than the first region and has a helix angle θ2 smaller than the helix angle θ1. The second region includes an elongated protruding part along the first flute.

A cutting tool may include a main body extended from a first end to a second end. The main body may be rotatable around a rotation axis. The main body may include a first cutting edge, a second cutting edge, a first flute and a second flute. The first flute may be extended from the first cutting edge toward the second end. The second flute may be extended from the second cutting edge toward the second end. The first flute may include a first hole located in the main body. The second flute may include a second hole located in the main body. The first hole may have a circular shape and the second hole may have a long narrow shape in a circumferential direction of the rotation axis in a cross section orthogonal to the rotation axis.

A drill includes a drill body having a longitudinal axis, a front end, and a frontend portion and at least one flute in the front end portion. A cutting insert is mounted to the drill body in each flute of the at least one flute at the front end of the drill body. The at least one flute includes a plurality of grooves, concave surfaces of adjacent ones of the grooves intersecting to define a ridge separating the grooves.

A drill body and a drill are disclosed. The drill body has a rotational axis and comprises a central chip flute extending along a periphery of the drill body. A central chip flute cross-section has a centre line extending in a plane extending perpendicularly to the rotational axis, and through the rotational axis. The central chip flute cross-section has a depth, as seen along the centre line, and a width as seen perpendicularly to the centre line. The central chip flute cross-section has a maximum depth Dp within a range of Dp=0.75×D/2 to Dp=0.90×D/2, and a maximum width W within a range of W=0.75×D/2 to W=0.90×D/2, and wherein the maximum width W extends symmetrically about the centre line.

A method of producing a drill has a step of preparing a workpiece to be processed to produce a drill, and a step of forming a ground groove. The workpiece has a cutting blade, a chip discharge flute helically extending, and a rake surface which have been formed therein. The drill is rotated around a drill axial center. The formation step rotates a rotary whetstone around its whetstone axial center, and grinds the rake surface to form the ground groove along the chip discharge flute. The formation step uses the rotary whetstone so that the whetstone axial center intersects a longitudinal direction of the chip discharge flute. The rotary whetstone has a rotating body shape projecting in a radial outward direction of the rotary whetstone axial center and around the rotary whetstone axial center.

A metal cutting indexable drill tool includes a drill body having a boring shaft. A center drill insert is mounted at a distal end of the boring shaft. A drill flute of the boring shaft is configured to direct and form a chip from the center drill insert, wherein the drill flute has a chip forming surface at a distal end thereof. The chip forming surface is arranged at a distance from a peripheral corner of the center drill insert to a point on a curve formed by the intersection of the chip forming surface and an imaginary inscribed sphere. The radius of the imaginary inscribed sphere, defined by the peripheral corner and the distance divided with the diameter of the drill tool is equal to a chip parameter A, which is indicative of the chip diameter to boring diameter ratio, wherein A is 0.3≤A≤0.5.

An auger includes a cylindrical body, a first channel helically defined in the cylindrical body, and a second channel helically defined in the cylindrical body. The auger further includes a first conduit defined in the cylindrical body. The first conduit includes a first sloped portion. The auger further includes a second conduit defined in the cylindrical body. The second conduit includes a second sloped portion. The auger further includes a first end mill formed in a first cavity defined in the cylindrical body, and a second end mill formed in a second cavity defined in the cylindrical body.

Provided is a body capable of suppressing the bending of the body during machining. A body includes: a first mounting part serving as a portion that is provided on a leading end side and has a cutting edge mounted thereon; and a second attachment part serving as a portion that is provided at a position different from a position of the first mounting part along a circumferential direction and has a guide pad attached thereto on the leading end side. One discharging groove that extends from the leading end side to a base end side and is used to guide and discharge a fluid to the base end side is formed on an outer peripheral surface of the body, and at least a part of the discharging groove is bent.

A rotary tool may include a base. The base may be extended from a first end to a second end. The base may include a first part and a second part. The first part may include the first end. The second part may have a larger outer diameter than the first part. The first part may include a first flute. The second part may include a second flute. In a first cross section of the first part, the first flute may include a first bottom part. A center of a first imaginary circle overlapping with the first bottom part may be located outside a circumscribed circle of the first part. In a second cross section of the second part, the second flute may include a second bottom part. A center of the second imaginary circle overlapping with the second bottom part may be located inside a circumscribed circle of the second part.