Cutting insert and cutting tool equipped with the same

A polygonal cutting insert comprising a top surface, a bottom surface, and a lateral surface connecting the top surface and the bottom surface, wherein:

• the top surface includes a corner portion, and a first edge portion and a second edge portion respectively extending from the corner portion;
• the corner portion includes a corner cutting edge, the first edge portion includes a first cutting edge, and the second edge portion includes a second cutting edge, respectively;
• a first raised portion and a second raised portion stepped from the first raised portion are formed on the top surface and along a center line connecting a center of the corner portion and a center of the top surface;
• the first raised portion is located closer to the corner portion than the second raised portion is, and the first raised portion is inclined downwardly from the second raised portion toward the corner portion;
• the second raised portion is formed at a higher position from the bottom surface than the first raised portion;
• and
• a side portion connected to the first raised portion is inclined downwardly from the second raised portion toward the first and second cutting edges;
• wherein a main breaker is provided in front of the first raised portion;
• and
• the main breaker protrudes from a corner cutting edge cutting surface of the corner cutting edge, a first cutting edge cutting surface of the first cutting edge, and a second cutting edge cutting surface of the second cutting edge, and
• includes a lower inclined surface connected to the corner cutting edge cutting surface, the first cutting edge cutting surface, the second cutting edge cutting surface, and an upper inclined surface connected to the lower inclined surface;
• and
• wherein a boundary line between the upper inclined surface and the lower inclined surface is formed at a position higher than the corner cutting edge, the first cutting edge, and the second cutting edge.