CUTTING INSERT, CUTTING TOOL, AND METHOD FOR PRODUCING CUT ARTICLE USING CUTTING INSERT AND CUTTING TOOL
A cutting insert according to an embodiment of the invention includes: an upper surface; a lower surface; a side surface which is connected to each of the upper surface and the lower surface, and includes a first side surface and a second side surface adjacent to each other; and a cutting edge including a major cutting edge located at an intersection of the upper surface and the first side surface, and a minor cutting edge located at an intersection of the upper surface and the second side surface. The upper surface includes a rake surface which is located along the major cutting edge, and is inclined downward as the upper surface separates from the major cutting edge. The second side surface includes a second upper constraining surface and a second lower constraining surface in order as the second side surface goes from the upper surface to the lower surface. The second upper constraining surface is inclined inward at an inclination angle ±1 with reference to a central axis extending between the upper surface and the lower surface. The second lower constraining surface is continuous with the second upper constraining surface, and is inclined outward at an inclination angle ±2 with reference to the central axis. A cutting tool with the cutting inserts, and a method of manufacturing a machined product by using the cutting tool are also provided.