A holder provided for mounting of a lathe cutter includes a carrier, a first joint seat, a second joint seat, a limit rod and a clamp member. The first and second joint seats are disposed on a first and second base of the carrier respectively. The lathe cutter is mounted between the first and second joint seats. The limit rod is inserted into a through hole of the lathe cutter, and a first and second ends of the limit rod are coupled to the first and second joint seats respectively. The clamp member is disposed on the limit rod. The clamp member and the second joint seat are provided to clamp the lathe cutter to separate the lathe cutter from the first and second bases.

A method of efficiently forming a finished part, the method includes providing a cutting tool having a first cutting edge extending from a first end of the cutting tool, a second cutting edge extending from a second end of the cutting tool, and a shaping edge disposed between the first cutting edge and the second cutting edge. The cutting tool is advanced into a rotating workpiece such that the first cutting edge removes a trailing end of the rotating workpiece, the shaping edge shapes a working portion of the rotating workpiece, and the second cutting edge removes the working portion of the rotating workpiece to form the finished part.

A method of efficiently forming a finished part, the method includes providing a cutting tool having a first cutting edge extending from a first end of the cutting tool, a second cutting edge extending from a second end of the cutting tool, and a shaping edge disposed between the first cutting edge and the second cutting edge. The cutting tool is advanced into a rotating workpiece such that the first cutting edge removes a trailing end of the rotating workpiece, the shaping edge shapes a working portion of the rotating workpiece, and the second cutting edge removes the working portion of the rotating workpiece to form the finished part.

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.

A cutting tool assembly having a longitudinal axis establishing upward and downward directions, includes a Y-axis parting adaptor mounted onto a holder. The parting adaptor has an insert pocket including a base jaw configured to support a cutting insert. The holder has a holder head portion and a shank portion. The holder head portion has an adaptor pocket in which the parting adaptor is mounted. If the holder shank cross-sectional shape is square or rectangular the forwardmost cutting edge is directly above the forwardmost holder shank surface, and if the holder shank cross-sectional shape is round and a centrally extending holder shank axis extends to the forwardmost cutting edge.

A cutting tool assembly having a longitudinal axis establishing upward and downward directions, includes a Y-axis parting adaptor mounted onto a holder. The parting adaptor has an insert pocket including a base jaw configured to support a cutting insert. The holder has a holder head portion and a shank portion. The holder head portion has an adaptor pocket in which the parting adaptor is mounted. If the holder shank cross-sectional shape is square or rectangular the forwardmost cutting edge is directly above the forwardmost holder shank surface, and if the holder shank cross-sectional shape is round and a centrally extending holder shank axis extends to the forwardmost cutting edge.

To provide a cutting insert such that a tool body can sufficiently hold the cutting insert even if one of cutting parts is broken. The cutting insert includes two side surfaces opposed to each other, a fixing hole passing through the centers of the two side surfaces, and an outer circumferential surface that is disposed between the outer circumferential edges of the two side surfaces and are connected to the outer circumferential edges of the two side surfaces. The outer circumferential surface includes four cutting parts, a first outer circumferential surface part that is disposed between the first cutting part and the second cutting part, and a second outer circumferential surface part that is opposed to the first outer circumferential surface part and is disposed between the third cutting part and the fourth cutting part. In a side view of the side surfaces from the axial direction of the fixing hole, the first outer circumferential surface part and the second outer circumferential surface part each have the center recessed toward the fixing hole, and a virtual arc having the same diameter as the diameter of the circumcircle of the cutting insert is in contact with two points on each of the outer circumferential surface parts.

A turning tool for metal cutting includes a tool body with an insert seat, a clamping member and a clamping pin. The clamping pin connects the tool body and the clamping member to clamp a cutting insert in the insert seat. A shaft of the clamping pin is axially movably received in the tool body bore and moveable to a first axial position. The clamping pin, in the first axial position, engages the clamping member and forces the clamping member towards a tool body top surface, to clamp the cutting insert in the seat. In the first axial position, a first coolant fluid outlet opening in the head is located above a top surface of the clamping member. A locking mechanism, in the first axial position, releasably locks the shaft in the bore preventing axial sliding toward the tool body top surface.

A turning tool for metal cutting includes a tool body with an insert seat, a clamping member and a clamping pin. The clamping pin connects the tool body and the clamping member to clamp a cutting insert in the insert seat. A shaft of the clamping pin is axially movably received in the tool body bore and moveable to a first axial position. The clamping pin, in the first axial position, engages the clamping member and forces the clamping member towards a tool body top surface, to clamp the cutting insert in the seat. In the first axial position, a first coolant fluid outlet opening in the head is located above a top surface of the clamping member. A locking mechanism, in the first axial position, releasably locks the shaft in the bore preventing axial sliding toward the tool body top surface.

A grooving or part-off tool assembly for Swiss-style machining includes a holder. The holder includes a resilient normally-closed holder clamp. In a preferred embodiment the holder clamp biases a blade holding a cutting insert against a pocket side abutment surface of a holder pocket.