Sumitomo Electric Hardmetal Corp.

Yoshinari Nagami

Atsuhiko Maeta

Yasuyuki Kanada

Tomoyuki Fukuyama

Yusuke Koike

Yuta Morisaki

Kouki Matsubara

Katsuya Nakakihara

Shota Tsujimoto

A cutting insert according to the present disclosure includes a first surface, a second surface, a side surface, and a cutting edge. The first surface has a rake face continuous to the cutting edge. The cutting edge has a corner cutting edge, a flat cutting edge, and a main cutting edge. The rake face has a first rake face portion, a second rake face portion, and a third rake face portion, the first rake face portion being continuous to the flat cutting edge, the second rake face portion being continuous to the main cutting edge, the third rake face portion being continuous to the corner cutting edge and being located between the first rake face portion and the second rake face portion. The rake face is provided with a level difference portion.

Cutting insert

A cutting edge has a corner cutting edge, a flat drag, and a main cutting edge. The rake surface has a first rake surface portion, a second rake surface portion, and a third rake surface portion. The first rake surface portion has a first inclined surface inclined at a first angle. The second rake surface portion has a second inclined surface inclined at a second angle greater than the first angle. The first end portion and the second end portion are higher than the reference surface in a direction perpendicular to the reference surface, and the main cutting edge extends so as to intersect the reference surface when viewed in a direction parallel to the reference surface. A first step portion rising from the third rake surface portion and continuous with the first rake surface portion is provided on the rake surface.

The cutting edge has: a corner cutting edge; a flat cutting edge continuous to a first end portion of the corner cutting edge; and a main cutting edge continuous to a second end portion of the corner cutting edge opposite to the first end portion of the corner cutting edge. The rake face has: a first rising surface portion; and a first rake face portion continuous to the first rising surface portion and located opposite to the corner cutting edge when viewed from the first rising surface portion. When viewed in a direction perpendicular to the reference surface, the first boundary includes a first line segment extending, from one of the flat cutting edge and the corner cutting edge, in a direction crossing a straight line extending along the main cutting edge.

To reduce burrs that may be formed at a corner portion of a machined surface in a face milling process, there is provided a cutting insert that does not tend to form burrs. A milling cutting insert includes cutting edges provided as ridges each defined by an upper or lower face and a side face that intersect each other, the cutting edges including a flat cutting edge. The cutting edge include a major cutting edge provided between adjacent ones of corner portions, the flat cutting edge provided at the corner portion, and a minor cutting edge provided between the major cutting edge and the flat cutting edge. A surface roughness of a side face that is continuous with the major cutting edge is higher than a surface roughness of a side face that is continuous with the minor cutting edge.

Milling cutting insert

An object is to provide a cutting insert for milling that has a minor cutting edge for wiping to achieve improved machined surface quality. A minor cutting edgeat a corner includes two circular cutting edge portionsandjoined to major cutting edgeson both sides of the corner and a straight cutting edge portionlocated between the two circular cutting edge portions. The cutting insert satisfies the following conditions: 0.05TA&#x2266;L&#x2266;0.4TA, 0.1L&#x2266;L&#x2266;0.5L, and h&#x2266;15 &#x3bc;m, where TA is the radius of a circle inscribed inside the major cutting edgesas viewed in the thickness direction of the cutting insert, Lis the length of the minor cutting edgein the longitudinal direction of the straight cutting edge portion, L is the length of the straight cutting edge portion, and h is the height of the minor cutting edge

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Itami, Japan

Yoshinari Nagami