A cutting insert of a substantially horizontal cylindrical segment shape and having top and bottom surfaces with a circular segment shape. The cutting insert has a convex side and a flat side, a top cutting edge which is formed where the convex side and the top surface meet, and a bottom cutting edge which is formed where the convex side and the bottom surface meet. The cutting insert includes a hole extending from the convex side towards the flat side. The hole is positioned at a center of a surface of the flat side.

Provided is a structure for improving accuracy in attaching a cutting tool to a body and making it possible to increase the number of blades while the cutting tool is mounted on the body. A cutting insert 1 includes: an upper surface 10 that has a shape with a lengthwise direction LD and a widthwise direction SD; a lower surface that is located opposite to the upper surface 10; a peripheral side surface 30 that is formed so as to connect the upper surface 10 and the lower surface; cutting edges 51 and 52 that are respectively formed on an intersecting ridge line of the upper surface 10 and the peripheral side surface 30, and on an intersecting ridge line of the lower surface and the peripheral side surface 30, and each have a curved ridge line that extends in a lengthwise direction thereof; and a through hole 60 that penetrates from the upper surface 10 to the lower surface. End surfaces 31 and 32 located in the lengthwise direction LD of the upper surface 10 and the lower surface, of the peripheral side surface 30, are respectively inclined with respect to the upper surface 10 and the lower surface, and are parallel to each other. A reference surface 33 that is located opposite to the cutting edges 51 and 52, of the peripheral side surface 30, is a flat surface that is orthogonal to the upper surface 10 and the lower surface.

A cutting insert has: an upper surface; a lower surface; a side surface, having a first surface and a second surface disposed opposite each other between the upper surface and the lower surface; and a first cutting edge. The lower surface has a plurality of slots extending from a side of the first surface to a side of the second surface. In addition, when viewed from a side of the lower surface, if the angle between a ridge line on which the upper surface and the first surface intersect and an imaginary extension line of the plurality of slots is defined as θ1, and the angle between a ridge line on which the lower surface and the first surface intersect and the imaginary extension line is defined as θ2, then θ2>θ1.

A cutting insert according to an embodiment of the present disclosure relates to a circular double-sided cutting insert including a top surface, a bottom surface, a lateral surface, and a cutting edge, and mounted to a cutting tool, in which a plurality of clearance surfaces and a plurality of fastening surfaces are located on the lateral surface, and among the plurality of fastening surfaces, a fastening surface, which is brought into contact with the cutting tool upon mounting of the cutting insert to the cutting tool, forms an acute angle with respect to the top surface or the bottom surface acting as a rake surface.

Provided is a cutting insert that can suppress damage of a corner cutting edge. The cutting insert has an approximately polygonal shape, and is constituted of a main cutting edge and a corner cutting edge connected to the main cutting edge. The cutting insert includes: a first side face portion that is connected to the main cutting edge, has a negative clearance angle, and is formed such that height thereof increases gradually in a direction of approaching the corner cutting edge; and a second side face portion that is connected to the corner cutting edge, has a negative clearance angle, and has height that is greater than the first side face portion.

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 includes an upper surface, a lower surface opposite to the upper surface, a first side surface and a second side surface configured to connect the upper surface and the lower surface, a mounting hole formed to penetrate the upper surface and the lower surface, a first cutting edge formed at an edge of the upper surface that meets the first side surface, and a second cutting edge formed at an edge of the upper surface that meets the second side surface. The lower surface includes a ridge portion, and a first inclined surface and a second inclined surface positioned on both sides of the ridge portion as a boundary. When looking at the lower surface, the first inclined surface and the second inclined surface have asymmetric shapes with respect to the ridge portion.

A straight line along the second line segment and a straight line along the fourth line segment form an acute angle. The straight line along the second line segment and the straight line along the third line segment form an obtuse angle. The straight line along the first line segment and the straight line along the fourth line segment form an obtuse angle. Each of the third curved portion and the fourth curved portion is larger in radius of curvature than the first curved portion and larger in radius of curvature than the second curved portion. In a direction perpendicular to the bottom surface, a distance between the top surface and the bottom surface is equal to a distance between the cutting edge and the bottom surface, or is shorter than the distance between the cutting edge and the bottom surface.

Railway wheel milling tool system including a railway wheel truing cutters and tangential railway wheel milling inserts are disclosed. The tangential milling inserts have at least four indexable cutting edges, each with a central wiper cutting edge segment between two convex cutting edge segments. The milling inserts may allow both the flat portion and curved portion of a railway wheel to be machined with an improved surface finish. The railway wheel truing cutters comprise a plurality of insert pockets structured and arranged to receive the tangential railway wheel milling inserts.

A method for milling a workpiece by way of at least one substantially polygonal cutting insert, which is arranged in a tool holder. A spindle axis of the tool holder encloses an angle of more than 0° with a plane normal to a machined workpiece surface. An effective lead angle between a main cutting edge of the cutting insert and the machined workpiece surface lies between 0° and 20°.