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.

To provide a cutting insert that is properly manufactured with ease of use. A cutting insert has a first end face, a second end face on the opposite side from the first end face, and a peripheral side surface that is parallel to a central axis connecting the center of the first end face and the center of the second end face and connects the first end face and the second end face. A first major cutting edge is formed on the outer edge of the first end face. A first flank facing the first major cutting edge is formed between the first major cutting edge and the peripheral side surface and has a negative clearance angle α with respect to the peripheral side surface. The peripheral side surface includes a first side surface facing the first flank. Between the first flank and the first side surface, a recess line is formed to extend along a virtual edge line where a virtual plane extending from the first flank and a virtual plane extending from the first side surface cross each other, and the recess line is formed with a notch on the virtual edge line.

A cutting insert for use in high-feed milling has a 180° rotational symmetry about a center axis and includes first and second major faces, a median plane extending between said major faces perpendicularly to the centre axis, a first main cutting edge and an associated first ramping cutting edge, and a second main cutting edge and an associated second ramping cutting edge. Each main cutting edge has a first end facing the associated ramping cutting edge and an opposite second end. Each ramping cutting edge has a first end facing the associated main cutting edge and an opposite second end. The cutting edges slope such that their second ends are located closer to the median plane than the respective first ends, and the second ends of the main cutting edges, are located closer to the median plane than the second ends of the ramping cutting edges.

Provided is a milling tool that allows a life of a tool main body to be elongated. The milling tool includes a replaceable cutting insert and a tool main body in which at least one insert seat that fixes the cutting insert is provided on a distal end side. The tool main body has a reinforcing wall covering at least a portion of the cutting insert when the cutting insert that is in a state of being fixed to the tool main body is viewed from the distal end side.

A rotary tool may include a holder and a cutting insert. The cutting insert may include an upper surface including a first upper side, a lower surface including a first lower side, and a lateral surface. The lateral surface may include a first lateral surface, a second lateral surface, and a third lateral surface. The first upper side may include a first end. The first end may be located closer to the third lateral surface than the second lateral surface. The first lower side may include a second end. The second end may be located closer to the second lateral surface than the third lateral surface. In a front view of the upper surface, the first lateral surface may include a tip region surrounded by the first end and the second end, and the tip region may be recessed toward the rear end.

A cutting insert may include a base member including a plurality of tungsten carbide particles. In cases where a particle diameter distribution of the tungsten carbide particles is measured at intervals of 0.025 μm, the particle diameter distribution may include, as a maximum peak and a second peak, a first peak value that appears in a particle diameter range of 0.5-0.9 μm, and a second peak value that appears in a particle diameter range of 1.1-1.5 μm. A value of a particle diameter distribution frequency is larger than zero at a valley part where a value of the particle diameter distribution frequency reaches a minimum between the first peak value and the second peak value.

A rotating tool according to an aspect of the present disclosure is a rotating tool used in a state held by a tool holder, and the rotating tool includes a shaft portion having an end attached to the tool holder, a blade attaching portion or a blade portion provided at an end of the shaft portion opposite to the end, and a plurality of sensors attached to the shaft portion, and the plurality of sensors include an acceleration sensor and a strain sensor.

A cutting insert may include a first surface, a second surface, a first lateral surface, a second lateral surface, a first cutting edge and a second cutting edge. The first lateral surface may include a first inclined surface located along the first cutting edge, a second inclined surface located along the first inclined surface, a third inclined surface located along the second cutting edge, a fourth inclined surface located along the third inclined surface, and a flat surface located along the second inclined surface and the fourth inclined surface. A second inclination angle of the second inclined surface may be smaller than a first inclination angle of the first inclined surface. A fourth inclination angle of the fourth inclined surface may be larger than a third inclination angle of the third inclined 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.

The present disclosure relates to a cutting insert, and a cutting insert according to the present disclosure comprises: an upper surface and a lower surface oriented in opposite directions; a first and a second shorter side surface connecting the upper surface and the lower surface to each other and oriented in opposite directions; a first and a second longer side surfaces connecting the upper surface and the lower surface to each other, connecting the first and the second shorter side surfaces to each other, oriented in opposite directions, and being longer than the first and the second shorter side surfaces; and a through hole extending through the upper surface and the lower surface, wherein when viewed toward the upper surface, the first longer side surface has two side portions, each side portion having an inclined shape with reference to the center portion.