An end mill includes: a columnar tool body that rotates about a center axis; and outer peripheral cutting edges on an outer peripheral surface of the tool body, the outer peripheral cutting edges including a first outer peripheral cutting edge and a second outer peripheral cutting edge. A relief angle θ of the first outer peripheral cutting edge changes to increase in an axial direction of the tool body from a bottom face that is one end of the tool body. A relief angle θ of the second outer peripheral cutting edge changes to decrease in the axial direction from the bottom face.

A burr includes a shaft portion and a milling portion. Cutters are separated by main flutes having a main flute depth. The cutters extend helically at a first twist angle. Each cutter has a cutting edge between a rake face and a relief face. The rake face forms a rake angle, and the relief face forms a relief angle. Chip breakers in each relief face have a chip breaker depth. At the largest diameter of the milling portion, the chip breaker depth is between 5 and 25 percent of the main flute depth, the rake angle is between −3 degrees and +14 degrees, the relief angle is between 10 degrees and 20 degrees, the first twist angle is greater than 25 degrees, and the number of main flutes is less than 15.

Indexable insert has a non-rectangular parallelogram shape with nearly rhombic basic shape and an imaginary intermediate plane spanned by four corners of an imaginary rhombus with sides running at a distance away from the upper side and the underside along the peripheral lateral surface in a plane such that each equivalent cutting edge has the same variation of distance and angle from the intermediate plane. Two diagonally opposing corners of both the upper side and the underside each have a greater distance from the intermediate plane than do the respective diagonally opposing corners of the upper side and the underside lying therebetween, and the diagonally opposing corners of the upper side and of the underside are shifted parallel to the intermediate plane and, as viewed in a plan view onto the intermediate plane, in mutually opposite directions away from the associated diagonals of the rhombus spanning the intermediate plane.

A surgical bur including flutes and lands. Each of the flutes includes a cutting edge, rake surfaces and a clearance surface. The rake surfaces of one of the flutes are decoupled from each other. Each of the lands is disposed between a pair of the flutes.

A replaceable face-milling head configured for rotating about a central rotation axis A.sub.R. The head includes a cutting portion and an integrally formed threaded shank-connector portion, the latter of which being configured for connecting to a shank. A length-diameter ratio LDR, defined as a cutting portion length L.sub.C divided by a cutting portion diameter D.sub.E, fulfills the condition: LDR≦1.00.

A cutting insert includes: two opposite end surfaces; a peripheral side surface extending between the end surfaces; and plural cutting edge sections that are formed along an intersecting ridgeline portion between the peripheral side surface and each of the end surfaces. Each of the cutting edge sections includes a corner cutting edge, a major cutting edge, and a minor cutting edge. A non-cutting intersecting ridgeline area extending between adjacent cutting edge sections on one end surface is located adjacent, via the peripheral side surface, to at least a part of the corner cutting edge and the major cutting edge of an associating cutting edge section on the other end surface.

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 shaft portion and a blade portion provided on a side surface of the shaft portion are included, and the blade portion includes cutting blades arranged in a plurality of lines on a side surface of the shaft portion along a peripheral direction, and arranged in a plurality of stages in an extending direction of a shaft center of the shaft portion in each line. Further, the cutting blade has a radial-direction clearance angle, a tip end-side clearance angle, and a base end-side clearance angle.

A double-sided cutting insert for milling has a first cutting edge formed at a transition from a top side to a circumferential lateral surface and a second cutting edge formed at a transition from a bottom side to the circumferential lateral surface. A reference plane (R) runs normal to an axis of symmetry (S). The cutting edges have main cutting edge portions and face cutting edge portions arranged in alternation, which extend between raised cutting corners and lowered cutting corners. The circumferential lateral surface has face free surfaces, which extend along the face cutting edge portion and which approach the axis of symmetry (S) with increasing distance from the associated face cutting edge portion. The circumferential lateral surface has main free surfaces, which extend along the main cutting edge portion and which move farther away from the axis of symmetry with increasing distance from the associated main cutting edge portion.

Disclosed is an indexable face milling cutting insert which comprises an insert body and a cutting body laminated on an upper surface of the insert body, and the insert body comprises multiple positioning side surfaces, an upper plane, and a positioning bottom surface; a projection of an edge of the positioning bottom surface, or an extension line thereof, on a rake face is intersected with a corresponding edge of the rake face, or an extension line thereof, to form a surface deflection angle and multiple flank faces are arranged between the rake face and the multiple positioning side surfaces, so as to avoid damaging the positioning side surfaces when a cutting edge is sharpened, thereby ensuring stability and long-term effect of a positioning reference, and a face cutting milling and a wiper face milling are applicable to a same face milling insert retaining slots.