A cutting tool for turning includes a coupling portion, an intermediate portion and a cutting portion. The intermediate portion extends along a longitudinal center axis thereof between the coupling portion and the cutting portion. The cutting portion includes a first and a second nose portion. The first nose portion has a first cutting edge, a second cutting edge, and a convex nose cutting edge connecting the first and second cutting edges. The first and second cutting edges form a nose angle less than 90°. A longitudinal center axis of the coupling portion defines a tool rotational axis. The cutting portion includes a top surface, the top surface facing away from the coupling portion and the first and the second nose portions each form free ends of the cutting tool.

A cutting tool for turning includes a coupling portion, an intermediate portion and a cutting portion. The intermediate portion extends along a longitudinal center axis thereof between the coupling portion and the cutting portion. The cutting portion includes a first and a second nose portion. The first nose portion has a first cutting edge, a second cutting edge, and a convex nose cutting edge connecting the first and second cutting edges. The first and second cutting edges form a nose angle less than 90°. A longitudinal center axis of the coupling portion defines a tool rotational axis. The cutting portion includes a top surface, the top surface facing away from the coupling portion and the first and the second nose portions each form free ends of the cutting tool.

A rotary cutting tool includes a tool shank, a replaceable cutting head mounted on the tool shank, a coupling pin, and an actuation member. In one embodiment, the coupling pin has a cylindrical portion with a reduced-diameter portion defined by a pair of angled side walls separated by a bottom surface for cooperating with a non-threaded portion at one end of the actuation member. In another embodiment, the coupling pin has a cylindrical portion with a notch with a pair of side walls for cooperating with a frustoconical member at one end of the actuation member. When assembled, a pair of V-shaped contact surfaces on the cutting head engage a pair of oppositely facing V-shaped contact surfaces on the tool shank to provide stability against the momentum created by cutting forces in two different directions and securely hold the cutting head in place during machining operations.

A rotary cutting tool includes a tool shank, a replaceable cutting head mounted on the tool shank, a coupling pin, and an actuation member. In one embodiment, the coupling pin has a cylindrical portion with a reduced-diameter portion defined by a pair of angled side walls separated by a bottom surface for cooperating with a non-threaded portion at one end of the actuation member. In another embodiment, the coupling pin has a cylindrical portion with a notch with a pair of side walls for cooperating with a frustoconical member at one end of the actuation member. When assembled, a pair of V-shaped contact surfaces on the cutting head engage a pair of oppositely facing V-shaped contact surfaces on the tool shank to provide stability against the momentum created by cutting forces in two different directions and securely hold the cutting head in place during machining operations.

A cutting insert for a cutting tool includes a body having a cutting edge, a rake face, and micro channels provided on the rake face adjacent the cutting edge. The micro channels define a grid pattern of micro channels that intersect each other in a region of the rake face where contact between a chip and the rake face is assumed to occur during cutting with the cutting insert.

A cutting tool includes a shaft portion. The shaft portion includes an increased-diameter portion having a diameter larger than a diameter of other portion of the shaft portion. The increased-diameter portion has a recessed portion formed in a peripheral surface of the increased-diameter portion.

A cutting tool includes a shaft portion. The shaft portion includes an increased-diameter portion having a diameter larger than a diameter of other portion of the shaft portion. The increased-diameter portion has a recessed portion formed in a peripheral surface of the increased-diameter portion.

A cutting insert may include a first surface, a second surface and a third surface. The first surface may include a corner having a convex curvilinear shape and an inclined surface. The inclined surface may include a first inclined surface, a second inclined surface and a third inclined surface. The first inclined surface may be inclined at a first angle. The second inclined surface may be inclined at a second angle. The third inclined surface may be inclined at a third angle. The first inclined surface may have a concave curvilinear shape in a cross section orthogonal to a bisector of the corner. The second inclined surface may be a flat surface. The second angle may be smaller than either of the first angle and the third angle in a cross section which includes the bisector and is orthogonal to the reference plane.

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.

The boundary flow path is constituted of a pair of boundary wall surfaces facing each other in a first cross section intersecting each of the first flow path, the boundary flow path, and the second flow path. An inclination of a tangent to at least one of the pair of boundary wall surfaces is continuously changed. In a second cross section perpendicular to a direction in which coolant flows, a lateral width of the first flow path is larger than a longitudinal width of the first flow path and a lateral width of the second flow path is larger than a longitudinal width of the second flow path when a longitudinal direction represents a direction in which the pair of boundary wall surfaces face each other and a lateral direction represents a direction perpendicular to the longitudinal direction.