A cutting tool body for indexable inserts, and a round milling insert, are configured not to cause floating or rattling upon mounting the milling insert. The tool body includes a recessed portion for fitting one of a plurality of protrusions thereto, the protrusions being formed in the milling insert to protrude in the radial direction. The recessed portion has two inner surfaces having curved portions disposed so the distance between them gradually decreases at the contact area between the recessed portion and the protrusion fitted thereto. The milling insert includes protrusions protruding radially, any of which fit into a recessed portion on a mounting seat of the tool body. The protrusions each have two curved outer surfaces arranged so the distance between them gradually decreases toward a tip of the protrusion, at the contact area between the protrusion and the recessed portion into which the protrusion is fitted.

A cutting insert has an upper surface having a long side, a short side, a lower surface, a lateral surface and a through hole. The lateral surface has a first lateral surface. The first lateral surface has a first plane that is overlapped with a central axis of the through hole in a front view and is parallel to the central axis, a second plane that is located closer to the short side than the first plane and is parallel to the central axis, a third plane that is located more away from the short side than the first plane and is parallel to the central axis, and a first inclined surface that is located between the second plane and the upper surface and comes closer to the central axis as coming closer to the long side. The first inclined surface is located away from the first plane.

In an embodiment, a cutting insert includes a body member and a cutting member. The body member is a columnar body, and includes: an upper surface; a lower surface; and an outer side surface between the upper surface and the lower surface. The cutting member is located at a corner part of the outer side surface in the body member. The cutting member includes: at least three surfaces being exposed; and a cutting edge at an intersecting portion of two of the at least three surfaces. The body member includes a through hole penetrating through the upper surface and the lower surface.

A cutting tool for face milling includes insert pockets for the fixing of cutting insert. The cutting inserts can be fixed in the insert pockets, wherein the cutting inserts and insert pockets are designed such that, when the cutting inserts are fixed within the corresponding insert pocket, each cutting insert presents: a primary and a secondary cutting edge. The intersection between the primary and the secondary cutting edge of one cutting insert being axially inwardly and radially outwardly offset from the intersection between the primary and the secondary cutting edge of another cutting insert. A lead angle defined between the primary and the secondary cutting edges is less than 30°.

A milling insert for a side and face milling tool includes an upper side defining an upper extension plane, a lower side defining a lower extension plane, and a side surface extending between the upper and the lower sides around a periphery of the insert that includes a main radial clearance surface, two opposite axial clearance surfaces and two corner clearance surfaces. At least one cutting edge is formed in a transition between the upper and the side surfaces, wherein each cutting edge includes a main cutting edge extending above the main radial clearance surface and two corner cutting edges extending above the corner clearance surfaces on opposite sides of the main cutting edge. The main cutting edge slopes downward toward a midpoint of the main cutting edge and the main cutting edge and the main radial clearance surface slope outward from the corner cutting edges toward the midpoint.

This invention relates to cutting tools used to machine materials to produce new surfaces and chips of removed material. Embodiments of this invention allow round rotating cutting inserts to be used in a more economical way, with improved accuracy, with improved sealing, and with greater ease of use. The rotary support device and cutting inserts may be used in either radial or tangential mounting types of cutters. It also provides a built-in, fully sealed means of fine adjustment of the cutting insert that is useful in some applications.

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°.

Indexable insert has a non-rectangular parallelogram shape with nearly rhombic basic shape and an imaginary intermediate plane spanned by four corners of an imaginary rhombus with sides running at a distance away from the upper side and the underside along the peripheral lateral surface in a plane such that each equivalent cutting edge has the same variation of distance and angle from the intermediate plane. Two diagonally opposing corners of both the upper side and the underside each have a greater distance from the intermediate plane than do the respective diagonally opposing corners of the upper side and the underside lying therebetween, and the diagonally opposing corners of the upper side and of the underside are shifted parallel to the intermediate plane and, as viewed in a plan view onto the intermediate plane, in mutually opposite directions away from the associated diagonals of the rhombus spanning the intermediate plane.

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.

A cutting insert of the present invention comprises: an upper surface and a lower surface; first and second lateral surfaces; first and second cutting edge parts; and corner cutting edges, wherein the first cutting edge part includes: a first main cutting edge for forming one end at a portion spaced farthest away from the corner cutting edge; a first sub-cutting edge connected to the corner cutting edge; and a first auxiliary cutting edge for connecting the first main cutting edge and the first sub-cutting edge so as to form a step between the same, and the first sub-cutting edge and the corner cutting edge form one straight line when viewed toward the first lateral surface, and are inclined upward in the direction opposite to the direction toward the lower surface while gradually going in the direction toward the second cutting edge part.