An indexable cutting insert has a central mounting portion and two cutting portions. The central mounting portion has opposing upper and lower surfaces. The lower surface has two abutment elements associated therewith, each abutment element having two diverging abutment surfaces forming two abutment angles. The two cutting portions extend away from the central mounting portion, have distal cutting edges, and are entirely located in diagonally opposite imaginary quadrants of four quadrants defined by two mutually perpendicular quadrant planes. Two abutment bisector planes bisecting the two abutment angles and one of the quadrant planes are parallel or coincident. In a top view, the two cutting portions extend away from the central mounting portion in opposite directions. Two cutting bisector lines parallel to the two directions and bisecting the two cutting edges are mutually offset. A cutting tool has an insert holder and the cutting insert removably retained therein.

The present invention provides a cutting tool that can firmly hold four types of cutting inserts by one tool main unit. A cutting insert of a cutting tool 1 has an approximately triangular stereoscopic shape including three corner portions. A tool main unit has a fixing portion that can selectively fix a plurality of types of cutting inserts, including: a negative type cutting insert of which angle of the corner portion exceeds 60°, a positive type cutting insert of which angle of the corner portion exceeds 60°; a negative type cutting insert of which angle of the corner portion is less than 60°; and a positive type cutting insert of which angle of the corner portion is less than 60°. The fixing portion has a bottom face that contacts with a bottom face of the cutting insert, and a side wall face that contacts with a side face of the cutting insert. A portion, which contacts with the cutting insert, of the side wall face of the fixing portion differs depending on the type of the cutting insert.

A machining tool includes a tool carrier with at least one seat receiving an exchangeable, indexable cutting insert. A fastening screw fastening cutting insert to seat has a head section for support on the cutting insert and a shaft section at least regionally having an external screw thread. The seat has a contact face supporting an underside of the cutting insert and at least one lateral bearing face supporting a side surface of the cutting insert. A through-hole is formed in the contact face, through which the shaft portion of the fastening screw extends. A clamping element is disposed on the tool carrier on the rear side of the contact face of the seat, in which an internal screw thread is formed, cooperating with the external screw thread of the fastening screw. The fastening screw and the clamping element can be jointly displaced in a displacement direction.

A tool system for machining includes a tool body that has a first end for connecting to a machine tool and a second end having an end face on which a seat for an interchangeable cutting insert is formed. The cutting insert has an underside formed as an abutment surface, a top side formed as a rake face, and an encircling side face formed as a flank, and a cutting edge is formed at a transition from the top side to the encircling side face. The cutting insert is arranged on the seat such that the top side extends perpendicularly to the longitudinal axis of the tool body and the cutting edge protrudes beyond the outer circumference of the end face of the tool body in a radial direction with respect to the longitudinal axis with two usable cutting corners and cutting-corner portions adjoining the latter on both sides.

A cutting insert is provided, comprising a top surface, a bottom surface, and side surfaces spanning therebetween, the side surfaces comprising one or more feed-facing side surfaces and one or more radial-facing side surfaces. The top surface is formed with one or more linear grooves, each constituting a chip breaker and being disposed parallel to and adjacent one of the feed-facing side surfaces. The chip breaker is characterized by a constant profile along the entire length of its respective feed-facing surface. Each of the feed-facing side surfaces is disposed at an acute feed-angle with respect to the top surface, and each of the radial-facing side surfaces being disposed at an acute radial-angle with respect to the top surface, the feed-angle being greater than the radial-angle.

A cutting tool includes a cutting insert resiliently clamped in an insert holder. The insert holder includes a forwardly located insert mounting portion that includes an insert receiving recess which extends along a recess axis. The insert holder includes a fastening member through hole opening out to the insert receiving recess. The insert receiving recess includes an insert orientation projection. The fastening member through hole has a through hole angular extent about the recess axis. The insert orientation projection has an insert orientation projection angular extent about the recess axis. The insert orientation projection angular extent at least partially angularly overlaps the through hole angular extent about the recess axis.

In a cutting tool having an indexable lay-down cutting insert with a central body portion and three circumferentially spaced apart cutting portions, the cutting insert is removably secured to an elongated holding portion of an insert holder. Each cutting portion has a cutting edge with first and second cutting end points, the cutting edge formed at the intersection of an upward facing rake surface and a radially outward facing relief surface. In a top view of the cutting insert, parallel imaginary first and second vertical planes containing the first and second cutting end points, intersect the central body portion at first and second body side points, which are located first and second cutting distances from the first and second cutting end points, respectively. Each of the first and second cutting distances is greater than twenty-five percent of the first radius of an imaginary first circle circumscribing the cutting insert.

A tool system for machining includes a tool body that has a first end for connecting to a machine tool and a second end having an end face on which a seat for an interchangeable cutting insert is formed. The cutting insert has an underside formed as an abutment surface, a top side formed as a rake face, and an encircling side face formed as a flank, and a cutting edge is formed at a transition from the top side to the encircling side face. The cutting insert is arranged on the seat such that the top side extends perpendicularly to the longitudinal axis of the tool body and the cutting edge protrudes beyond the outer circumference of the end face of the tool body in a radial direction with respect to the longitudinal axis with two usable cutting corners and cutting-corner portions adjoining the latter on both sides.

A tool body to which a replaceable cutting insert is fixed includes: a holder: an insert mounting seat that is provided on a first surface of the holder; a clamp member that constrains the cutting insert placed on the insert mounting seat; and an operating member that presses a pressure receiving surface of the clamp member. The clamp member has the pressure receiving surface, a spherical head portion that is formed into a spherical crown shape, and a hook portion that protrudes to a side opposite to a side of the spherical head portion when seen from a side of the first surface. The insert mounting seat supports the clamp member to be swingable with the spherical head portion as a fulcrum, and the hook portion contacts a diameter reducing portion that is formed on an inner peripheral surface of an mounting hole for the cutting insert in a state in which the pressure receiving surface is pressed.

A tool body in which a cutting insert can be replaced easily is provided. The tool body which fixes the indexable cutting insert includes an insert mounting seat which is provided on a first surface of the tool body, a clamp member which binds the cutting insert placed on the insert mounting seat, and an operating member which operates the clamp member. The operating member can lower the clamp member from the first surface toward a second surface of the tool body on an opposite side thereof to the first surface and can raise the clamp member from the second surface toward the first surface. The clamp member has a hook portion which is brought into contact with a diameter reducing portion formed on an inner peripheral surface of a mounting hole of the cutting insert in a state where the clamp member is lowered.