A bur with features that minimize the application of substantially identical forces to the tissue against which the bur is applied. One of these features is the arrangement of the flutes so that one pair of flutes projects outwardly from the tip at an acute angle that is greater than the angle at which the other flutes project outwardly from tip. Consequently at the equator of the bur head, the location along the bur head where the bur head has a maximum diameter, the flutes define a perimeter that is non-circular in shape.

A tool damper for a machine tool, such as a milling machine, is arranged around the tool stem of the machine or the tool holder of the machine and arranged to damper vibrations of the tool.

A cutting tool includes a main body. The main body includes a distal end surface, a rear end surface, and a side surface. A spiral first groove and a spiral second groove are formed on the side surface of the main body. The first groove has at least four installation surfaces. The first installation surface is located on a most rear end surface side. The second installation surface is located closer to a distal end surface side with respect to the first installation surface. A length from the first installation surface to the second groove in a circumferential direction along the rotation direction of the main body is set to a first length. A length from the second installation surface to the second groove in the circumferential direction is set to a second length. The first length is longer than the second length.

An end mill includes a plurality of teeth and flutes. The teeth and their associated flutes include one or more correlated physical parameters. One such correlated parameter is that, at an axial location in a front half of an effective cutting length, at least one tooth of the plurality of teeth has a rake angle smaller than an average rake angle value of the plurality of teeth, and, at the same axial location, a flute preceding each such tooth has a helix angle larger than an average helix angle value of the plurality of flutes.

In one embodiment, a holder includes a body part elongated from a first end part to a second end part along a rotation axis. The body part includes a first member, a second member, and a third member. The first member is located on a side of the first end part, and includes a pocket to receive a cutting insert. The second member is located closer to the second end part than the first member, and includes at least one cavity inside the second member. The third member is located closer to the second end part than the second member.

An end mill includes a plurality of teeth and flutes. The teeth and their associated flutes include one or more correlated physical parameters. One such correlated parameter is that, at an axial location in a front half of an effective cutting length, at least one tooth of the plurality of teeth has a rake angle smaller than an average rake angle value of the plurality of teeth, and, at the same axial location, a flute preceding each such tooth has a helix angle larger than an average helix angle value of the plurality of flutes.

A damper includes a damper body that is configured to be attached to a workpiece during a machining process. A first side of the damper body is configured to abut a first side of the workpiece. The damper body includes a frame forming an outer periphery of the damper body, a plurality of damper nodes with a cavity in each damper node positioned in the frame, and a plurality of ribs extending between the frame and the damper nodes. A damping material is positioned in the cavity of each damper node.

Maximum values of actual machining allowances of a workpiece in respective cutting flutes are averaged by control amounts of respective cutting flutes calculated by an arithmetic unit. The arithmetic unit converts the calculated control amounts into an amount in each axis direction and subtracts the value from a feed axis command value in an NC program stored in a storage unit. Then, a numeral value control unit performs machining by controlling respective feed axes based on the subtracted feed axis command value.

A side milling cutter for slot cutting is provided whose vibration can be damped even in cases where a vibration mode of the cutter generates plural nodes in a cutting part. A side milling cutter for slot cutting of the present invention includes a disc-shaped cutter and a plurality of cartridges as cutting edges provided at a predefined interval in a circumferential direction along an outer circumference of the disc-shaped cutter. The disc-shaped cutter cuts a predefined slot on a workpiece using the cartridges by circumferentially rotating. The disc-shaped cutter internally includes a plurality of vibration damping structures in the circumferential direction on a disk surface of the disc-shaped cutter.

A roughing end mill includes: an end mill main body rotated about an axis; and four or more of outer peripheral cutting edges provided on an outer circumference of a tip part of the end mill main body spaced apart in a circumferential direction, each of the outer peripheral cutting edges extending from a tip of the end mill main body to a rear side, wherein each of outer peripheral cutting edges includes a waveform cutting edge that is concaved and convexed in a radial direction, a phase is shifted within one pitch, and the waveform cutting edges of the outer peripheral cutting edges have one or more parts, in which phases of the waveform cutting edges are sequentially shifted multiple times toward a rear end side of the end mill main body, and shifted the same multiple times toward a tip end side of the end mill main body.