Provided is a cutting insert and a cutting tool equipped with the cutting tool improving the force to clamp the insert and improving the strength of the insert and the chip dischargeability. The cutting insert includes: an upper surface, which is a first end surface; a lower surface, which is a surface on an opposite side to the upper surface, and is a second end surface having an installing surface for installing a cutting tool; a screw hole which has an axial line penetrating from the upper surface to the lower surface; a peripheral side surface which is formed such that the upper surface and the lower surface are connected; a major cutting edge and an inner cutting edge which are formed in an intersecting region between the upper surface and the peripheral side surface, and an intersecting region between the lower surface and the peripheral side surface, respectively; and a constraining surface which is formed on the peripheral side surface so as to at least partially contact with a body. An angle of the major cutting edge and an angle of the constraining surface are different in a top view viewed from the upper surface, and the angle of the major cutting edge is smaller than the angle of the constraining surface.

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.

A cutting insert includes an upper surface, a lower surface, a side surface, and a cutting edge. The upper surface includes a first side part, a second side part, and a corner part located between the first side part and the second side part. The side surface is located between the upper surface and the lower surface. The cutting edge is located at an intersection of the upper surface and the side surface. The cutting edge includes a first cutting edge located at the corner part, and a second cutting edge adjacent to the first cutting edge and located at the first side part. A height of the first cutting edge relative to the lower surface is constant. The second cutting edge is inclined toward the lower surface as going toward the corner part.

What is presented is a cutting insert including a polygonal plate-shaped insert main body that includes: two polygonal surfaces; a side surface; and a cutting edge, the insert main body has a mounting hole that is centered on an insert center line passing through centers of the two polygonal surfaces, the cutting edge includes a major cutting edge extending from a first end of a corner edge located at a corner of the polygonal surface, and, in the opening of the mounting hole, a plurality of protrusions protruding with respect to a boss surface around an opening of the mounting hole are formed at intervals in a peripheral direction in an inner periphery side region of the major cutting edge.

A cutting insert has an insert major body which includes two hexagonal faces facing each other and six side faces arranged around the two hexagonal faces, and is rotationally symmetrical at 120° intervals about an insert center line passing through centers of the two hexagonal faces and inversely symmetrical in front and back with respect to the two hexagonal faces, wherein a major cutting edge and an minor cutting edge are alternately formed in a circumferential direction in the single hexagonal face at twelve intersecting ridgeline portions at which the hexagonal faces and the side faces intersect, the major cutting edge is formed to be located at an intersecting ridgeline portion with one hexagonal face while the minor cutting edge is formed to be located at an intersecting ridgeline portion with the other hexagonal face at a single side face.

Provided is a cutting insert, which has excellent chip discharge performance even when formed with multiple corners superior in economic efficiency. A first ridgeline at which an upper surface and a circumferential side surface intersect each other includes a plurality of corners disposed at equal intervals and a plurality of main cutting edges disposed one by one between the corners adjacent to each other. A distance between the corners adjacent to each other is equal to or less than 60% of the diameter of a circle inscribed within the ridgeline. The main cutting edges includes a first cutting edge that is linearly formed and a second cutting edge that is linearly formed. The length of the second cutting edge is equal to or less than half the length of the first cutting edge and is positioned closer to a center side of the cutting insert than an extension line of the first cutting edge is. The circumferential side surface includes a first side surface facing the first cutting edge and a second side surface facing the second cutting edge. A clearance angle of the first side surface is smaller than that of the second side surface.

In an end view, a cutting insert 10 comprises a first connecting part 30A which is inclined such that the first connecting part 30A travels in a first direction as it heads away from a second peripheral side surface part 18 and approaches a fourth peripheral side surface part 22, and also comprises a second connecting part 30B which is connected to a center point serving as an end of the first connecting part 30A and which is inclined such that the second connecting part 30B travels in a third direction as it heads away from the second peripheral side surface part 18 and approaches the fourth peripheral side surface part 22. A cutting edge 24 comprises: a first cutting edge part 24A which is formed on the first connecting part 30A so as to be distant, by a first distance L1, from a virtual plane PR1 including a center point C1; a second cutting edge part 24B which has, in a side view, a concave circular-arc shape having a second curvature radius smaller than a first curvature radius and which is formed on the second connecting part 30B so as to be distant, by a second distance L2 greater than the first distance L1, from the virtual plane PR1; and a third cutting edge part 24C connecting the first cutting edge part 24A and the second cutting edge part 24B.

A single-sided three-way indexable milling insert for 90° shoulder milling operations, includes a positive basic shape, a rake surface, a peripheral surface including side abutment surfaces, a base bearing surface and a screw hole connecting the rake and base bearing surfaces. The insert has three main cutting edges which lie along an imaginary equilateral triangle. A material volume V.sub.F of the cutting insert and a void volume V.sub.S of the insert's screw hole fulfill the condition V.sub.S/V.sub.F≥0.30.

A cutting insert may include a first surface having a polygonal shape, a second surface, a third surface and a cutting edge. The first surface may include a first corner, a first side, a first inclined surface located along the first side, and a second inclined surface located along the second side. In a plan view of the first surface, a width of the first inclined surface in a direction orthogonal to the first side may become larger as approaching the second side. A width of the second inclined surface in a direction orthogonal to the second side may become larger as approaching the first side.

A cutting insert 2 comprises a peripheral side surface 30 which is parallel to a central axis O of a first end surface 10 and a second end surface 20. The peripheral side surface 30 comprises a first side surface 31 facing a first major cutting edge 11, a second side surface 32 facing a first wiper edge 12, and a third side surface 33 facing a first inner edge 13. A flank 311 of the first major cutting edge 11 and a flank 321 of the first wiper edge 12 are inclined such that the flank 311 and 321 approaches the central axis O as it heads toward the first end surface 10. The flank 311 of the first major cutting edge 11 is located on a different plane from the first side surface 31. The flank 321 of the first wiper edge 12 is located on a different plane from the second side surface 32. Meanwhile, a flank of the first inner edge 13 is located on the same plane as the third side surface 33.