A cutting insert 10 comprises a peripheral side surface 16 comprising a plurality of peripheral side surface parts 16A-16H formed so as to be in rotational symmetry with respect to a central axis AX. In the cutting insert 10, a second end surface 14 is provided with a plurality of inclined surface parts 13A-13H formed so as to be in rotational symmetry with respect to the central axis AX and to be recessed from a peripheral edge part 14A.

A cutting insert includes a rake face, a seating face facing an opposite side to the rake face and seated on an insert mounting seat, and a flank face extending around the rake face and the seating face, in which two cutting edges each having an arcuate cutting edge portion extending in an arc shape and a linear cutting edge portion which is in contact with the arcuate cutting edge portion are formed on an intersecting ridgeline portion between the rake face and the flank face, a groove portion having a wall surface coming into contact with a projection portion protruding from a bottom surface of the insert mounting seat is formed on the seating face, and the groove portion has a narrow width portion in which a groove width decreases from one end side toward the other end side in a direction in which the groove portion extends.

A cutting insert for a milling tool including an upper side having a central surface, a lower side, a peripheral side surface, and a cutting edge formed between the upper side and the peripheral side surface. The cutting edge having a positively inclined main cutting edge projecting at least partly above the central surface. The upper side includes a rake surface extending inside of and along the at least one cutting edge, sloping downward toward the central surface. A plateau, elevated with respect to the central surface and extending along the main cutting edge, is formed inside the rake surface. A transition between the rake surface and the plateau extends at an angle .sub.2 with respect to an upper extension plane, wherein .sub.2>0.

A cutting insert includes a rake end surface having four corners and, in a center thereof, a central surface portion. A supporting end surface has four corners and, in a center thereof, a central supporting surface portion. A peripheral side surface extends between the rake end surface and the supporting end surface. The peripheral side surface includes two opposing major side surfaces. A hole extends through the cutting insert from one of the major side surfaces to the other of the major side surfaces, wherein the central surface portion is disposed at a greater distance from a central axis (A) of the hole than is the central supporting surface portion. The single-sided cutting insert has a corner radii or cutting edge radii that extend over at least a quarter of a width of the cutting insert.

An indexable cutting insert has opposing upper and lower end surfaces, and a peripheral surface including three side surfaces circumferentially alternating with three corner surfaces. The three side surfaces define an imaginary triangle and an imaginary hexagon. Each corner surface intersects the upper end surface to form an upper corner peripheral edge having a primary cutting edge. In a top view, each triangle side traverses two upper corner peripheral edges, imaginary lines tangential to the end points of each primary cutting edge are either collinear or form an obtuse angle greater than 175 degrees, each primary cutting edge has a primary length greater than half the hexagon side length, and at least one triangle side traverses each primary cutting edge. The insert is removably secured in a rotary cutting tool such that one of the upper corner peripheral edges contains an axially forwardmost point of the insert's upper peripheral edge.

A cutting insert 10 comprises a peripheral side surface 16 comprising a plurality of peripheral side surface parts 16A-16H formed so as to be in rotational symmetry with respect to a central axis AX. In the cutting insert 10, a second end surface 14 is provided with a plurality of inclined surface parts 13A-13H formed so as to be in rotational symmetry with respect to the central axis AX and to be recessed from a peripheral edge part 14A.

A cutting insert includes a rake face, a seating face facing an opposite side to the rake face and seated on an insert mounting seat, and a flank face extending around the rake face and the seating face, in which two cutting edges each having an arcuate cutting edge portion extending in an arc shape and a linear cutting edge portion which is in contact with the arcuate cutting edge portion are formed on an intersecting ridgeline portion between the rake face and the flank face, a groove portion having a wall surface coming into contact with a projection portion protruding from a bottom surface of the insert mounting seat is formed on the seating face, and the groove portion has a narrow width portion in which a groove width decreases from one end side toward the other end side in a direction in which the groove portion extends.

A compression milling cutter includes a shank and a front cutting portion that terminates at a leading end of the milling cutter. The front cutting portion has a first circumferential row of one or more insert receiving pockets proximate a leading end of the milling cutter, and a second circumferential row of one or more insert receiving pockets, each insert receiving pocket configured to receive a respective indexable cutting insert. The cutting insert mounted in the first circumferential row has a positive axial rake angle, A, and the indexable cutting insert mounted in an insert pocket of the second circumferential row has a negative axial rake angle, B. Because of the different axial rake angles, chips generated during a machining operation flow in opposite directions, thereby creating a compression zone disposed between the first and second circumferential rows. This compression zone replicates the cutting action of a solid end mill, particularly when machining fiber reinforced plastic materials.

A cutting tool has a cutting body with a first insert pocket and an indexable cutting insert removably mounted therein. The first insert pocket has a first seat surface with a plurality of first engagement elements and a first support wall transverse thereto. The cutting insert has upper and lower surfaces and a boundary surface extending therebetween. The lower surface has a plurality of lower engaging elements and the boundary surface has a plurality of alternating first and second peripheral surfaces intersecting the upper surface to form first and second upper cutting edges. In each index position with the lower surface in contact with the first seat surface, the first support wall prevents translation of the cutting insert in a first direction, and the first engagement elements eccentrically contact the lower engaging elements to prevent translation of the cutting insert in a second direction perpendicular to the first direction.

A cutting insert includes a rake end surface having four corners and, in a center thereof, a central surface portion. A supporting end surface has four corners and, in a center thereof, a central supporting surface portion. A peripheral side surface extends between the rake end surface and the supporting end surface. The peripheral side surface includes two opposing major side surfaces. A hole extends through the cutting insert from one of the major side surfaces to the other of the major side surfaces, wherein the central surface portion is disposed at a greater distance from a central axis (A) of the hole than is the central supporting surface portion. The single-sided cutting insert has a corner radii or cutting edge radii that extend over at least a quarter of a width of the cutting insert.