A beveling cutter can include a body with a shaft hole formed through the center. The cutter can also include a plurality of 10 cutter blades arranged at predetermined distances on the circumferential surface of the body, each having a radial primary blade with a radial primary relief angle (a) ranging from about 5 to about 15 degrees and a radial secondary blade with a radial secondary relief angle (b) ranging from about 16 to about 30 degrees. The cutter can also include discharge grooves formed longitudinally between the cutter blades to discharge chips produced in beveling, and a key groove formed at a portion inside the body, in which the helix angle (d) of the cutter blades ranges from about 5 to about 45 degrees. With the beveling cutter, it is possible to smoothly discharge chips produced in beveling and to prevent damage to the cutter blades.

A corner radius end mill includes a blended gash extending along a cutting edge. The blended gash is formed in a corner sector of the end mill. The corner sector has a first half-sector and a second half-sector defined on opposite sides of an imaginary bisection line of the corner sector, the first and second half-sectors subtending equal angles about the imaginary bisection line. The blended gash extends from a first extremity and blends an end gash surface and flute rake surface of the corner radius end mill. The blended gash is spaced from a radial tangent point by a predetermined distance, and extends to a second extremity which is spaced apart from the axial line and the second half-sector.

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.

An indexable rotary cutting tool and insert is capable of performing a high-accuracy cutting process with high efficiency. A twist angle of an outer peripheral cutting edge of the tool has a positive value, an axial rake angle of the cutting edge of a corner R of the tool at a boundary point between the cutting edge of the corner R and the outer peripheral cutting edge has a positive value, the axial rake angle of the cutting edge of the corner R at a reference point has a negative value, and the radial rake angle at least between the boundary point and the reference point in an entire edge length region of the cutting edge of the corner R has a negative value. The radial rake angle at the reference point is smaller than the radial rake angle at the boundary point.

In one aspect, elongated rotary cutting tools such as end mills are described herein which may provide one or more advantages over prior designs. For example, in some embodiments, cutting tools described herein can provide reduced wear rates at corner cutting edges, may permit high ramp angles during processing up to and including 45 ramp angles, and/or increased tool life.