A cutter head structure includes a cutting edge portion including a cutting body. An outer surface of the cutting body is a curved surface which protrudes forwardly. The outer surface of the cutting body is provided with a first cutting edge and at least two second cutting edges. The first cutting edge extends from one side of the cutting body to a top region of the cutting body and then to the other side of the cutting body. The second cutting edges are respectively disposed on both sides of the first cutting edge. First chip flutes are defined between the first cutting edge and the second cutting edges adjacent thereto, and each of the first chip flutes has a width gradually increasing from the top region to both ends of the cutting body.

The purpose of the present invention is to perform machining on a double-curved surface to have good finished surface characteristics while achieving high speed feeding. An end mill (2) is provided with a bottom blade (2A) formed in a curved convex and circular arc shape, and a radius blade (2B) located at the edge and formed in a circular arc shape. The bottom blade (2A) has a region where a blade part is not formed on the axis of the end mill (2), and the end mill (2) is further provided with a center blade (2C) in the region of the bottom blade (2A). The center blade (2C) is formed in a circular arc shape with a radius smaller than that of the circular arc part of the bottom blade (2A).

It is an object of the present invention to provide a rotary cutting tool that can divide chips at an appropriate size, suppress the incidence of edge chipping and damage attributed to chips to the cutting tool and a workpiece, extend the tool service life with regard to the machining of hard, brittle materials, and improve machining efficiency. The rotary cutting tool includes a hard coat film 3 coated onto a tip end section of a tool body 1 having a chip discharge groove 2. A rake face 6 is concavely provided in a cutting edge-side chip discharge groove formation surface 4 constituting the chip discharge groove 2 of the tool body 1, from a cutting edge 5 and along the cutting edge 5.

Provided is an end mill which includes an end mill main body having a bottom blade having a convex hemispherical shape, and a hard coating film coated on at least a surface of a distal end portion of the end mill main body. A diameter D (mm) of the bottom blade is 2 mm or less. A ratio W/D of a width W (mm) of a chisel portion to the diameter D (mm) is within a range of 0.020 to 0.060. A ratio L/D of a facing length L (mm) of chip discharge grooves to the diameter D (mm) is within a range of 0.014 to 0.090. A rake angle of the bottom blade in a range in which a chisel edge is formed in the chisel portion is within a range of −15° to −30°.

The present invention provides an end mill including: a shaft-shaped end mill main body; a chip discharge groove extending from a leading end to a trailing end in an axial direction of the end mill main body; a bottom blade which is provided at a leading end portion in the axial direction of the end mill main body and has a spherical shape in which a rotation locus around the axis has a center on the axis; and an outer peripheral blade which is provided along the chip discharge groove, and in which a rotation locus around the axis is convex outward. A curvature radius of the rotation locus of the outer peripheral blade is larger than a curvature radius of the rotation locus of the bottom blade. A twist angle of the outer peripheral blade is 20° or more.

A processing apparatus for processing a workpiece includes a tool holding part 9 for holding a tool 3 for processing a workpiece 5, a transferring part 11 for transferring the tool 3 for processing the workpiece 5 with the tool 3, and a control unit 13 for controlling the transferring part 11 so as to transfer the tool 3 with respect to the workpiece 5 on the basis of an NC program, and in the NC program, an arithmetic expression for calculating the position of the tool 3 is incorporated and the program is corrected on the basis of the relationship between the cutting transferring distance, the wear amount, and the deflection amount in addition to the contour error of the tool 3.

The present invention relates to a cutting tool, which performs, like a drill or a ball end mill, cutting while rotating in a state in which the center of the tip end is in contact with a work material, and includes a wear-resistant layer formed at the tip end thereof, wherein a portion of the wear-resistant layer is selectively removed through tip end polishing from the center of the tip end of the drill or the ball end mill to a predetermined area, so as to restrain micro-brittle wear generated in an ultra-low speed region, and thus remarkably improving the cutting lifespan of the cutting tool such as the drill or the ball end mill.

The present invention relates to a cutting tool, which performs, like a drill or a ball end mill, cutting while rotating in a state in which the center of the tip end is in contact with a work material, and includes a wear-resistant layer formed at the tip end thereof, wherein a portion of the wear-resistant layer is selectively removed through tip end polishing from the center of the tip end of the drill or the ball end mill to a predetermined area, so as to restrain micro-brittle wear generated in an ultra-low speed region, and thus remarkably improving the cutting lifespan of the cutting tool such as the drill or the ball end mill.

A method for forming a depression into a glass object for storing cremated remains may include coating a metal sphere with diamond dust. The method may include spinning the diamond dust coated metal sphere via a spindle and motor arrangement. The method further may include pressing the spinning diamond dust coated metal sphere against at least one face of the glass object. Furthermore, the method may include applying coolant while pressing the spinning diamond dust coated metal sphere against at least one face of the glass object. The continuous spin and pressure of the diamond dust coated metal sphere against at least one face of the glass object grinds the depression into the glass object.

A tapered end mill includes an outer circumferential cutting edge, a flute is disposed such that a flute bottom radius defined as a distance between a flute bottom and the tool axis decreases from a shank side toward the tool tip side, the flute bottom radius linearly changes at a predetermined gradient angle in the tool axis direction, the gradient angle changes at a predetermined change point to become smaller on the tool tip side as compared to the shank side, and a gradient angle θ1 on the tool tip side relative to the change point is equal to or larger than 0° and smaller than a taper half angle α of a cutting portion provided with the outer circumferential cutting edge, and a gradient angle θ2 on the shank side relative to the change point is larger than the taper half angle α.