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 bull mill cutter includes a cutter bar and a cutter head. The cutter head has one end mounted to the cutter bar. The cutter head includes a main body and a number of cutter teeth mounted on the main body. A quantity of the cutter teeth is equal to a positive integer within a range from 8 to D*15. D is equal to a diameter of the main body of the cutter head in millimeters.

An end mill configured as a high feed circle segment cutter and a high feed end cutter utilizable in 5-Axis machining. The end mill comprises the end work of a high feed mill and the fluting of a circle segment cutter, thereby allowing the operator to rough out the bulk of the material with a high feed method (small axial and larger radial depths of cuts), then use the side of the tool to finish/semi-finish the walls of the part with the circle segment cutter geometry on the side of the tool.

When a closed type impeller is manufactured from one block, a rough cutting process of cutting a flow path region of a block using a rough cutting tool, and a residue-cutting process of cutting a cutting residue in the cutting process using a residue-cutting tool are executed. The residue-cutting tool has a tool main body having a blade formed on an outer periphery thereof, and a handle having the tool main body fixed to a distal end thereof. A maximum outer diameter of the tool main body is larger than a minimum outer diameter of the handle. Further, the tool main body has a rear blade directed in a direction including a tool rear side component.

[Object] To provide a ball end mill in which it is possible to improve wear resistance in the vicinity of the central axis at the tip of a ball-nosed end cutting edge and to suppress vibration of a tool body during machining. [Solution] A ball end mill 10 includes: a tool body 1 that rotates about a central axis O; and an arc-shaped ball-nosed end cutting edge 2 in a side view which is provided to start from the central axis O side on a tip side of the tool body 1 toward a rear side thereof. The ball-nosed end cutting edge 2 has a radius of curvature r that becomes gradually smaller from the central axis O side toward a periphery Q side.

A cutter for electrode graphite which has a shank at one end and a tool tip at the other end, and flutes extending from the shank to the tool tip, which space machining lands apart from each other in the circumferential direction. The tool tip is formed as a ball head section, in which the machining lands have a rounded contour, extending along a ball head radius. At least one of the machining lands is a rough-machining land and at least one other of the machining lands is a fine-machining land. Each machining land has a circumferential working area with a cylindrical surface-segment-shaped shell surface, the working area of each rough-machining land is a circumferential file with teeth which are worked into the shell surface of the working area, and the working area of each fine-machining land exterior grooves extends with a twist about the tool axis.

Provided is a coated cutting tool, comprising: a substrate; and a coating layer formed on at least part of a surface of the substrate. The coating layer includes at least one composite nitride layer including a compound having a composition represented by (Ti.sub.xAl.sub.y)N [x denotes an atomic ratio of a Ti element based on a total of the Ti element and an Al element, y denotes an atomic ratio of the Al element based on a total of the Ti element and the Al element, and 0.10x0.50, 0.50y0.90, and x+y=1 are satisfied]. The composite nitride layer includes a phase having a lattice constant of from 0.400 nm or more to 0.430 nm or less, and a phase having a lattice constant of from 0.755 nm or more to 0.810 nm or less.

A multi-flute ball end mill of the present invention includes: a shank portion configured to rotate about a rotational axis; a cutting edge portion; three or more ball edges formed on the cutting edge portion; gashes formed between the ball edges; peripheral cutting edges continuous with end portions of the ball edges on the shank portion side; and flutes formed between the peripheral cutting edges continuously with the gashes. The degree of curvature of the ball edges is 35% to 55%. Each of the gashes includes four faces of a rake face of each of the ball edges, a gash wall face, a first gash face, and a second gash face. The second gash face is formed such that the closer the second gash face is to the rotation center point, the more inwardly the second gash face enters a second face of each of the ball edges.

In manufacturing a three-dimensional layered formative object by forming solidified layers obtained by irradiating material powder with energy beam to solidify the material powder, laminating the solidified layers and performing a cutting process on the laminated solidified layers, a cutting tool used in a process of scraping off a finishing allowance from the solidified layers cut with the finishing allowance left comprises: a columnar part; a cutting part connected to an end of the columnar part, having a maximum radius centered on a central axis of the columnar part larger than a maximum radius of the columnar part, and having a blade for cutting; and a diameter enlargement part located at a boundary between the columnar part and the cutting part, and having a radius continuously enlarged from the columnar part toward the cutting part. The maximum radius of the diameter enlargement part is smaller than the maximum radius of the cutting part.

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.