The rotary cutting tool of the invention has helicoidal peripheral cutting edges with a wavy profile.

A cutting tool includes a shaft portion and a plurality of edge region groups. The ridgeline between the first rake face portion and the first flank face portion constitutes a first cutting edge portion. The ridgeline between the second rake face portion and the second flank face portion constitutes a second cutting edge portion. As seen from the direction perpendicular to a plane tangent to the outer peripheral surface, in a state where the central axis overlaps a first end on the front end side of the first cutting edge portion, the inclination angle of the first cutting edge portion relative to the central axis is larger than the inclination angle of a straight line relative to the central axis, the straight line connecting the first end to a second end on the front end side of the second cutting edge portion.

A rotatable cutting tool for machining of a honeycomb core includes a front end; a rear end; a peripheral surface extending between the front and rear ends; a set of helical flutes formed in the peripheral surface at a first helix angle 4565, having a first depth; and a set of helical ridges. At least one helical groove formed in the peripheral surface at a second helix angle 90<100, has a second depth, which is smaller than the first depth. The at least one helical groove intersects the helical ridges so that a plurality of cutting teeth are formed on each helical ridge. Each cutting tooth includes a second ridge formed in a transition between two lands, a cutting edge and a clearance edge join in a tooth tip constituting the radially outermost point of the cutting tooth.

A rotary tool of the present aspect has a body and a cutting edge positioned on the outer periphery of the body. The cutting edge has a first section and a second section when viewed on an imaginary plane defined by cutting a rotational trajectory of the rotary tool on a plane including a rotational axis. The first section has a first region and a second region. A first radius of curvature of the first region is greater than a second radius of curvature of the second region in at least one of a plurality of the first sections.

The invention relates to a method for producing a cooling channel piston, wherein a blank of the cooling channel piston, which has a cavity designed as a cooling channel, is provided and wherein an inlet or outlet opening is introduced into the blank in the direction of the cooling channel, characterized in that the opening is introduced into the blank by means of a CNC-controlled circular milling process by using a special milling cutter having end cutting edges arranged in a shaft profile.

A cutting tool according to one aspect of the present disclosure includes a shaft portion and cutting edge portions. The main cutting edge portions have a main cutting edge. In a section within ?30% of a blade length of a region from a center of the region in a direction along the central axis, the main cutting edge portions have first and second nick portions. The main cutting edge portions are formed in the region. The relationship between the first nick portion and the second nick portion satisfies at least one of a first condition and a second condition. The first condition is that a width of the first nick portion is different from a width of the second nick portion. The second condition is that a depth of the first nick portion is different from a depth of the second nick portion.

A formed rotary cutting tool includes a cutting edge defining a cutting edge diameter that is increased and reduced in a direction of an axis of the tool, so as to have at least one neck portion in which the cutting edge diameter is minimized. The cutting tool includes a roughing portion which is provided on a periphery thereof and which is constituted by a succession of protrusions and recesses arranged in the direction of the axis. The roughing portion includes (i) a fine roughing portion that is provided in at least one of the at least one neck portion, and (ii) another portion that is provided in a portion that is other than the at least one of the at least one neck portion. The fine roughing portion of the roughing portion is different in characteristics from the above-described another portion of the roughing portion.

A cutting tool includes a shaft portion and a plurality of edge region groups. The ridgeline between the first rake face portion and the first flank face portion constitutes a first cutting edge portion. The ridgeline between the second rake face portion and the second flank face portion constitutes a second cutting edge portion. As seen from the direction perpendicular to a plane tangent to the outer peripheral surface, in a state where the central axis overlaps a first end on the front end side of the first cutting edge portion, the inclination angle of the first cutting edge portion relative to the central axis is larger than the inclination angle of a straight line relative to the central axis, the straight line connecting the first end to a second end on the front end side of the second cutting edge portion.

A rotary cutting tool has a cutting tool body with a cutting end and a cutting portion adjacent to the cutting end. The cutting portion includes a first blade, which has a first finishing cutting portion and a first roughing cutting portion adjacent to the first finishing cutting portion. The cutting portion includes a second blade, which has a second finishing cutting portion and a second roughing cutting portion adjacent to the second finishing cutting portion. The first finishing cutting portion overlaps one or both of the second finishing cutting portion and the second roughing cutting portion. The first roughing cutting portion overlaps one or both of the second roughing cutting portion and the second finishing portion.

A one-piece cutting tool has a shank portion with a mounting end and a cutting end. The cutting end has a body portion and a substantially hemispherical portion. The cutting end further comprises a plurality of flutes, each flute helically extending adjacent to one another about the cutting end along a length from the body portion to the hemispherical portion. Each flute has a cutting edge divided into a first cutting edge section and a second cutting edge section, the first cutting edge section extending along the body portion and being substantially straight-edged or serrated, and the second cutting edge section extending along the hemispherical portion and being serrated along at least a part of the hemispherical portion. A cutting tool assembly is also provided.