A cutting insert suitable for a small-diameter milling tool is provided. A cutting insert has a rake face, a bottom surface, a circumferential side surface, and a through hole. A first ridgeline at which the rake face and the circumferential side surface intersect each other includes a first main cutting edge, and a first corner cutting edge connected to a tip of the first main cutting edge. The bottom surface includes a first bottom surface that comes closer to the rake face gradually toward a side at which the first main cutting edge is located when viewed from a central axis of the through hole, and a second bottom surface that comes closer to the rake face gradually toward a side opposite to the first main cutting edge when viewed from the central axis. A distance between a virtual intersection line, at which a first virtual surface formed by extending the first bottom surface and a second virtual surface formed by extending the second bottom surface intersect each other, and the first main cutting edge decreases from a tip side, at which the tip of the first main cutting edge is located, toward an end side, at which an end opposite to the tip is located, in an extending direction of the first main cutting edge.

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.

An insert may include a first surface, a second surface, a ridge line located at an intersection of the first surface and the second surface. The first surface may include a first corner, a first side and a second side. The ridge line may include a corner cutting edge located on the first corner, a first cutting edge located on the first side, and a second cutting edge located on the second side. The first surface may further include a first region located from the first cutting edge toward a midportion of the first surface, a second region located from the second cutting edge toward the midportion of the first surface, and a concave part located on at least one of the first region and the second region.

An object of this disclosure is to provide a cutting insert that is shaped so that a major cutting edge is not damaged easily. In the cutting insert, a major cutting edge, a corner edge, a flat cutting edge and an inner cutting edge are formed on at least an upper surface, a protruding portion protruding outward is formed in a major cutting edge side surface portion of a side surface that corresponds to the major cutting edge, and a first section is formed in which, when viewed from above, the protrusion amount becomes smaller as the protruding portion separates from the corner edge. Furthermore, the cutting insert includes a first clearance angle changing portion in which a clearance angle becomes smaller as a major cutting edge flank portion formed in a major cutting edge side surface portion separates from the corner edge, and a second clearance angle changing portion in which the clearance angle becomes larger as the major cutting edge flank portion separates from the corner edge, wherein the first clearance angle changing portion is preferably positioned closer to the corner edge than the second clearance angle changing portion is, and, of end portions of the first clearance angle changing portion, the value of the clearance angle at a distal end portion from the corner edge is preferably negative.

An insert may include a first surface, a second surface, a ridge line located at an intersection of the first surface and the second surface. The first surface may include a first corner, a first side and a second side. The ridge line may include a corner cutting edge located on the first corner, a first cutting edge located on the first side, and a second cutting edge located on the second side. The first surface may further include a first region located from the first cutting edge toward a midportion of the first surface, a second region located from the second cutting edge toward the midportion of the first surface, and a concave part located on at least one of the first region and the second region.

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.

Disclosed is an indexable face milling cutting insert which comprises an insert body and a cutting body laminated on an upper surface of the insert body, and the insert body comprises multiple positioning side surfaces, an upper plane, and a positioning bottom surface; a projection of an edge of the positioning bottom surface, or an extension line thereof, on a rake face is intersected with a corresponding edge of the rake face, or an extension line thereof, to form a surface deflection angle and multiple flank faces are arranged between the rake face and the multiple positioning side surfaces, so as to avoid damaging the positioning side surfaces when a cutting edge is sharpened, thereby ensuring stability and long-term effect of a positioning reference, and a face cutting milling and a wiper face milling are applicable to a same face milling insert retaining slots.

It is an object of the present invention to provide a rotary cutting tool that can divide chips at an appropriate size, suppress the incidence of edge chipping and damage attributed to chips to the cutting tool and a workpiece, extend the tool service life with regard to the machining of hard, brittle materials, and improve machining efficiency. The rotary cutting tool includes a hard coat film 3 coated onto a tip end section of a tool body 1 having a chip discharge groove 2. A rake face 6 is concavely provided in a cutting edge-side chip discharge groove formation surface 4 constituting the chip discharge groove 2 of the tool body 1, from a cutting edge 5 and along the cutting edge 5.

A cutting insert has an upper surface, a lower surface and a lateral surface. The upper surface has a first upper side, and a second upper side. The lower surface has a first lower side and a second lower side. The lateral surface has a first lateral surface, a second lateral surface, and a third lateral surface. The first lateral surface has a first concave part having a first constraining surface having a flat shape. The second lateral surface has a second concave part having a second constraining surface having a flat shape. The third lateral surface has a convex part. The first concave part and the second concave part are separated from each other by the convex part.

An insert may include a first surface, a second surface, a ridge line located at an intersection of the first surface and the second surface. The first surface may include a first corner, a first side and a second side. The ridge line may include a corner cutting edge located on the first corner, a first cutting edge located on the first side, and a second cutting edge located on the second side. The first surface may further include a first region located from the first cutting edge toward a midportion of the first surface, a second region located from the second cutting edge toward the midportion of the first surface, and a concave part located on at least one of the first region and the second region.