A cutting tool according to the present disclosure has a rake face, a flank face, and a cutting edge. The cutting edge is located between the rake face and the flank face. The cutting tool includes a substrate composed of a cubic boron nitride sintered material, and an oxide layer that covers the substrate and that constitutes at least part or whole of the rake face, the flank face, and the cutting edge. The oxide layer includes at least one element selected from a group consisting of titanium, aluminum, zirconium, and cobalt. A thickness of the oxide layer is 2 μm or less.

According to one implementation, an end mill for orbital drilling includes: a shank; a first cutting edge formed in a peripheral portion of the shank; and a second cutting edge formed in a bottom portion of the shank. At least a chamfered edge is formed on a first ridgeline between a first rake face and a first flank of the first cutting edge.

According to one implementation, an end mill for orbital drilling includes: a shank; a first cutting edge formed in a peripheral portion of the shank; and a second cutting edge formed in a bottom portion of the shank. At least a chamfered edge is formed on a first ridgeline between a first rake face and a first flank of the first cutting edge.

A rotary cutting tool includes a shaft having and outer surface and having a longitudinal axis, a plurality of helical flutes formed in the shaft about the longitudinal axis, a plurality of helical cutting edges formed at an interface with the outer surface and a respective helical flute about the longitudinal axis, and a plurality of end cutting edges located on an axial distal end of a cutting portion of the shaft, the end cutting edges being contiguous with a corresponding one of the plurality of helical cutting edges and forming a corner in the transition between each of the end cutting edges and the corresponding one of the plurality of helical cutting edges. A hone edge extends along a portion of each of the end cutting edges, the associated corner and a portion of the corresponding one of the plurality of helical cutting edges.

A rotary cutting tool includes a shaft having and outer surface and having a longitudinal axis, a plurality of helical flutes formed in the shaft about the longitudinal axis, a plurality of helical cutting edges formed at an interface with the outer surface and a respective helical flute about the longitudinal axis, and a plurality of end cutting edges located on an axial distal end of a cutting portion of the shaft, the end cutting edges being contiguous with a corresponding one of the plurality of helical cutting edges and forming a corner in the transition between each of the end cutting edges and the corresponding one of the plurality of helical cutting edges. A hone edge extends along a portion of each of the end cutting edges, the associated corner and a portion of the corresponding one of the plurality of helical cutting edges.

A rotary cutting tool includes a shaft having and outer surface and having a longitudinal axis, a plurality of helical flutes formed in the shaft about the longitudinal axis, a plurality of helical cutting edges formed at an interface with the outer surface and a respective helical flute about the longitudinal axis, and a plurality of end cutting edges located on an axial distal end of a cutting portion of the shaft, the end cutting edges being contiguous with a corresponding one of the plurality of helical cutting edges and forming a corner in the transition between each of the end cutting edges and the corresponding one of the plurality of helical cutting edges. A hone edge extends along a portion of each of the end cutting edges, the associated corner and a portion of the corresponding one of the plurality of helical cutting edges.

Radius mill and cutting work method that includes a plurality of end cutting edges arrayed around a central axis O and a plurality of arc-shaped radius end cutting edges continuous with the end cutting edges on an outer peripheral side in a radial direction. The end cutting edge is divided into an inner peripheral side end cutting edge and an outer peripheral side end cutting edge in a radial direction. Second surfaces of the plurality of inner peripheral side end cutting edges are coupled at a part close to the axis O. A region of coupled second surfaces is continuous from a region including the axis O to outer peripheral sides of respective inner peripheral side end cutting edges in a radial direction in a strip shape. A width of the strip-shaped region gradually enlarges from axis O side to an outer peripheral side in a radial direction.

The present invention provides a more practical hard-coated cutting tool having improved cutting performance during finishing so as to obtain a better finished surface. Provided is a hard-coated cutting tool including a tool body (7) coated with a hard coating (4) and having a cutting edge (3) formed on a ridge line intersecting a flank face (1) and a rake face (2). In the hard-coated cutting tool, the thickness h1 of the hard coating (4) on the flank face (1) side and the thickness h2 of the hard coating (4) on the rake face (2) side near the cutting edge (3) satisfies conditions 8 mh130 m and 0h2/h10.5 in a cross-section perpendicular to the cutting edge (3) in a range equal to or less than 0.3 times the tool diameter in the axial direction from the tip of the tool.

Milling tools configured to increase surface roughness are disclosed. The tool may include an elongated body having a longitudinal axis and a plurality of cutting inserts coupled to the body and spaced along the longitudinal axis, each cutting insert having a cutting edge. In one embodiment, the cutting edges may have an orientation that is oblique to the longitudinal axis of the elongated body. Each cutting edge may have a first end having a greater cutting radius than a second end. The cutting edges may be offset from the longitudinal axis of the elongated body by an offset angle. In another embodiment, the cutting edges may have a textured or rough surface profile. For example, the cutting edges may have a mean roughness (Rz) of at least 7.5 m. The milling tools may increase the surface roughness of a milled engine bore to facilitate a subsequent rough honing process.