Abstract: A cutting insert includes an upper surface and a lower surface. The upper surface includes a first corner, a first side, a rake face, and a rising surface. The rising surface includes a first recessed portion recessed with respect to the first side, a first protruding portion located farther from the first corner than the first recessed portion, a second protruding portion located between the first protruding portion and the first side, and a first stepped portion located between the first protruding portion and the second protruding portion. The first protruding portion has a first front end portion located closest to the first side. A cross section orthogonal to the first side and including the first front end portion is a first cross section. At the first cross section, the second protruding portion is located closer to the lower surface than the first protruding portion.

Abstract: A cutting insert may include a first surface, a second surface, a third surface and a cutting edge. The first surface may include a corner, a first side, a first inclined surface located along the corner, a second inclined surface located further inside than the first inclined surface, a third inclined surface located along the first side, a fourth inclined surface located further inside the first surface than the third inclined surface, and a protruded part located further inside than the second inclined surface and the fourth inclined surface. An inclination angle of the protruded part may be smaller than an inclination angle of the second inclined surface in a cross section along a bisector of the corner. The inclination angle of the protruded part may be larger than a third inclination angle in a cross section orthogonal to the first side.

Abstract: A cutting tool holder may include an upper surface; a first side surface; a second side surface adjacent to the first side surface; a pocket opening into the upper surface, the first side surface, and the second side surface; a first portion located lower than the pocket and protruded outward from the first side surface; and a flow path including an inflow port and an outflow port. The first side surface may include a first recess. The flow path may include a first outflow port opening into the first portion as the outflow port and a first flow path extending from the first outflow port into the holder. The first outflow port is located at a region of the first portion corresponding to the first recess.

Abstract: A cutting tool may include a holder including a pocket, a cutting insert located at the pocket, a clamp member configured to fix the cutting insert to the pocket, and a flow path including an inflow port and an outflow port. The clamp member may include a screw and a clamp. The flow path may further include a first flow path located in the holder, a second flow path located in the clamp, and a third flow path that is a pipe connecting the first flow path and the second flow path and including a first end part located in the first flow path and a second end part located in the second flow path.