The objective of the present invention is to provide a cutting insert which reduces cutting load and can be accurately positioned at a coupling part of a cutting tool even if cutting edges are broken or deformed. To this end, the cutting insert of the present invention includes an upper surface, a lower surface, a plurality of lateral surfaces connecting the upper surface with the lower surface, and a plurality of upper cutting edges formed between the plurality of lateral surfaces and the upper surface. In addition, the cutting insert coupled with the coupling part of the cutting tool includes: first and second upper cutting load reducing portions formed on the upper surface and provided at each side coming in contact with first and second upper cutting edges of the plurality of upper cutting edges facing each other so as to reduce the cutting load; and a one side position setting portion provided on a first lateral surface of the plurality of lateral surfaces not coming in contact with the first and second upper cutting edges so as to set the position of the cutting insert in the coupling part.

Provided are a cutting insert and a tool holder on which the cutting insert is provided. The cutting insert includes a circular upper surface, a circular lower surface, a cylindrical lateral surface for connecting the upper surface and the lower surface, an upper cutting edge formed between the upper surface and the lateral surface, a lower cutting edge formed between the lower surface and the lateral surface, and a plurality of rotation-preventing parts provided at the lateral surface so as to prevent the cutting insert from rotating with respect to the tool holder. Each rotation preventing part includes an inner curved surface recessed toward the center of the lateral surface and convexly rounded so as to form concentric circles in conjunction with the lateral surface, and a stepped rotation-preventing surface parallel to the axial direction of the insert and connecting the inner curved surface and the lateral surface.

A cutting insert (20) for a milling cutter (10) is described, wherein the cutting insert (20) comprises a first main surface (22) for abutment against a stop surface (24) oriented substantially perpendicular to the direction of rotation of the milling cutter (10), a second main surface (26) which is opposite to the first main surface (22), which comprises the cutting surface, and a lateral surface (28) which connects the first main surface (22) with the second main surface (26) and which comprises the free surface. The lateral surface (28) has at least one clamping section (38) by which the cutting insert (20) is clamped in a recess (18) in a tool body (12) by means of a clamping element (40), in particular wherein the cutting insert (20) is a turning cutting insert. Furthermore, a milling cutter (10) is described.

A cutting tool includes a cutting insert having an anti-rotation stopping indent formed in a transition between a bottom surface and a side surface thereof and includes a first stop surface. The insert seat has at least one anti-rotation stop, which protrudes with respect to a side wall of the insert seat and includes a second stop surface. The anti-rotation stop is arranged to inhibit rotation of the cutting insert in the insert seat by contact between the first and second stop surfaces. The second stop surface is completely located within the anti-rotation stopping indent when the cutting insert is mounted. As seen in a section perpendicular to a common central axis, an angle of less than 180° is formed between a tangent to the second stop surface and a tangent to the first duct at a transition between the two.

A cutting insert for a rotary cutting tool has a second surface that includes a second seating surface having a shape of a flat surface. The first cutting edge has a first main cutting edge portion and a first sub cutting edge portion. The second cutting edge has a second main cutting edge portion and a second sub cutting edge portion. When viewed in a direction from the first surface toward the second surface, at least a portion of the second sub cutting edge portion is located outside the first main cutting edge portion, and at least a portion of the first sub cutting edge portion is located outside the second main cutting edge portion. When viewed in the direction from the first surface toward the second surface, each of the first sub cutting edge portion and the second sub cutting edge portion has a shape of a curved line.

In a cutting tool rotatable about a tool axis, a reversible cutting insert is removably secured in a tool body. The cutting insert has opposing top and bottom end surfaces interconnected by a peripheral surface, and a median plane located therebetween. The peripheral surface includes four side surfaces alternating with four corner surfaces, the side and corner surfaces intersecting the top surface to form top major cutting edges and top corner cutting edges, respectively. Each side surface has a median surface and a top major relief surface. Each top major relief surface forms an acute internal top major relief angle with the median plane, and the median plane intersects the four median surfaces to define an imaginary median square. In a top end view of the cutting insert, the four top major cutting edges define an imaginary top major square rotationally offset from the imaginary median square.

A cutting insert for a shoulder milling tool has a trigonal shape and includes a first surface, a second surface, and a circumferential surface extending between the first surface and the second surface. The circumferential surface includes a countersunk circumferential waist portion. The circumferential surface has a first and a second clearance surface extending along a first and a second main cutting edge. Each of the first and second clearance surfaces forma a negative nominal clearance angle. Each of the first and second main cutting edges is arranged inside the countersunk circumferential waist portion, as seen in the view towards the first and second surfaces, respectively.

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 rotary tool according to an aspect includes a body, a flank face positioned at a side of a tip end of the body, a flute extending from the flank face toward a rear end of the body, and a ridge line positioned at an intersection of the flank face and the flute. The ridge line includes a recessed portion recessed toward the rear end of the body, an inner edge extending from the recessed portion toward the tip end of the body, and an outer edge extending from the recessed portion toward an outer periphery of the body. The flute includes a recessed groove extending along the outer edge. The recessed groove is connected to the recessed portion and the outer edge, and is separated from the inner edge.

A cutting tool includes a toolholder and a cutting insert. The toolholder includes a toolholder pocket having a pocket wall including a first anti-rotation engagement surface and a second anti-rotation engagement surface. The cutting insert is mounted in the toolholder pocket. The cutting insert includes: an upper surface, the upper surface having a plurality circular sinusoidal cutting edges; a lower surface opposite the upper surface; and an exterior sidewall between the upper surface and the lower surface. The first anti-rotation engagement surface and the second anti-rotation engagement surface of the pocket wall of the toolholder engage the exterior sidewall of the cutting insert to resist rotation of cutting insert.