Cutting inserts are disclosed having four cutting edges and milling tools comprising the cutting inserts installed in pockets on a rotatable cutting tool holder. The cutting inserts comprise a front face, a rear face and four side faces extending between the front and rear faces. A cutting edge is provided at the intersection of the front face and each side face. Each cutting edge comprises a plurality of cutting edge segments, including a facet cutting edge that forms the flat surface of a workpiece being milled, and a straight lead cutting edge that extends at an angle away from the facet cutting edge. The lead cutting edge angle is selected to provide effective milling of the workpiece at entry. The cutting inserts have side seating surfaces that allow the inserts to be more stably supported in cutting insert pockets.

A rotary cutting tool includes a cutting head having a plurality of insert-receiving pockets for radially mounting a first type of cutting insert in a first cutting region and for tangentially mounting a second type of cutting insert in a second cutting region. The first cutting region has a first length, L1, and the second cutting region has a second length, L2, that is greater in magnitude than the first length, L1. The two types of cutting inserts provides a hybrid cutting insert design in which the first type of cutting inserts provide an increased chip gash volume for effective chip evacuation, and the second type of cutting inserts provide an increased core diameter to minimize deflection of the rotary cutting tool.

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.

An insert adaptor is configured for providing secure clamping of an insert in an insert pocket. The insert adaptor is configured to be located between an insert and an insert pocket and includes at least one magnetic surface configured for applying a magnetic attraction force to the insert pocket or a shim.

A toolholder (10) has a pocket (20) that accommodates two styles of cutting inserts (25, 25′) having different clearance angles (CA). A support pad (78, 80) protrudes from two side walls (82, 84) of the pocket (20). Each support pad (78, 80) includes a first, planar wall (78a, 80a) and a second, planar wall (78b, 80b) formed at a composite angle defined by a first angle (92) and a second angle (94). The first, planar wall (78a, 80a) enables the pocket (20) to accommodate the second style of cutting insert (25′), and the second, planar wall (78b, 80b) enables the pocket (20) to accommodate the first style of cutting insert (25). In one aspect, the support pads (78, 80) extend the entire length, L, of the support pad (78, 80). In another aspect, an indentation (112, 114) divides one or both of the support pads (178, 180) into two portions, each portion having two planar walls (178a, 178b, 178c, 178d, 180a, 180b, 180c, 180d).

A reversible cutting insert for milling has first and second cutting edges formed at the transitions from the top and bottom surfaces to a lateral face. The cutting insert has a 4-fold rotational symmetry. A reference plane extends perpendicular to the axis of symmetry. The cutting edges have four cutting edge portions. One cutting edge portion is a main edge and a wiper edge that are connected by a rounded cutting corner. The first and second cutting edges are at the greatest distance from the reference plane in the region of the cutting corners. Main and wiper clearance faces directly adjoin an assigned main edge and wiper edge, respectively, in the circumferential lateral face. Exterior angles between the main clearance faces and the reference plane are greater than exterior angles between the wiper clearance faces and the reference plane.

An indexable cutting insert is suitable for vertical and oblique machining. The cutting insert has top and bottom surfaces, first to fourth side surfaces extending between the top and bottom surfaces, and a screw hole passing through the top and bottom surfaces. The top surface has a mounting surface of a flat surface. The top and bottom surfaces are rotationally symmetric with each other. A cutting edge is formed at a junction between the top surface and the adjacent first and second side surfaces. A non-cutting edge is formed at a junction between the top surface and the adjacent third and fourth side surfaces. The first and second side surfaces form an acute angle with a plane extending from the mounting surface of the top surface. The third and fourth side surfaces form an obtuse angle with the plane extending from the mounting surface of the top surface.

A double-sided cutting insert for milling which has eight main cutting edges and eight wiper edges. The cutting insert includes top and bottom faces and four side faces. Each side face includes first and second sub-faces inclined with respect to each other. The first sub-face has a main cutting edge adjacent to the top face and a wiper edge adjacent to the bottom face. The second sub-face has a wiper edge adjacent to the top face and a main cutting edge adjacent to the bottom face. The wiper edge of the second sub-face is inclined inwardly relative to the cutting insert with respect to the main cutting edge of the first sub-face. The wiper edge of the first sub-face is inclined inwardly relative to the cutting insert with respect to the main cutting edge of the second sub-face.

A cutting insert includes an insert peripheral surface that includes at least one planar major insert side abutment surface and an insert lower surface that includes an anti-slip recess recessed therein. The anti-slip recess includes at least one elongated and straight anti-slip groove. Each major insert side abutment surface is oriented parallel to a groove longitudinal axis of a respective anti-slip groove. An insert holder includes a holder pocket. The holder pocket includes a pocket peripheral surface which includes planar major pocket side abutment surface and a pocket base surface having an elongated and straight anti-slip rib. When the cutting insert is releasably attached to the insert holder, to constitute a fastened position of a cutting tool, the anti-slip rib is located in the anti-slip groove that is oriented parallel to the major insert side abutment surface that abuts the major pocket side abutment surface.

The invention relates to a cutting insert having a polygonal upper side. Cutting edges, which are alternately configured as roughing cutting edges and finishing cutting edges, are provided at the edges of the upper side. The finishing cutting edges define an incircle (K1) having a diameter that is enlarged in comparison to a nominal size of the cutting insert, and the roughing cutting edges define an incircle (K2) having a diameter that is reduced in comparison to the nominal size of the cutting insert. The invention further relates to a cutting tool having a tool body on which at least one such cutting insert is disposed.