Insert and cutting tool

A cutting tool, comprising:

• a holder which has a length extending from a first end to a second end, and which comprises a pocket located on a side of the first end;
• and
• an insert located in the pocket, the insert comprising:
• a first surface,
• a second surface connecting to the first surface, and
• a cutting edge located on at least a part of a ridgeline between the first surface and the second surface, wherein
• the first surface comprises, at a position away from the ridgeline, a groove elongated, in an extending direction of the groove, from a first end part closest to the cutting edge to a second end part farthest away from the cutting edge,
• the groove comprises
• an opening located in the first surface, and
• a bottom surface,
• a distance from the bottom surface to the opening is a groove depth, and a length of the groove in the extending direction of the groove is a groove length,
• the groove comprises, at a position closer to the first end part than a half of the groove length,
• a first groove part where the groove depth increases going from the second end part toward the first end part, and
• a second groove part where the groove depth decreases going from the second end part toward the first end part, and
• the first groove part is located closer to the second end part than the second groove part.

An insert, comprising:

• a first surface,
• a second surface connecting to the first surface, and
• a cutting edge located at an intersection of the first surface and the second surface, wherein
• the first surface comprises a groove separated from the cutting edge and having an opening and a bottom surface,
• the groove is elongated along an extending direction intersecting the cutting edge,
• the groove comprises
• a first end part closest to the cutting edge in the extending direction,
• a second end part farthest away from the cutting edge in the extending direction,
• a central part located at an intermediate position between the first end part and the second end part,
• a first groove part located between the first end part and the central part, and
• a second groove part located between the first end part and the first groove part,
• a distance from the bottom surface to the opening is a groove depth,
• the groove depth of the first groove part increases going toward the first end part, and
• the groove depth of the second groove part decreases going toward the first end part.