Cutting tool and method of manufacturing machined product using the same

A cutting tool, comprising:

• a cutting insert comprising an upper surface, a lower surface and a cutting edge located on at least part of sides of the upper surface;
• and
• a holder comprising an upper jaw and a lower jaw that respectively fix the cutting insert from the upper surface and the lower surface at a front end part in a longitudinal direction thereof,
• wherein at least one of an upper contact part of the upper surface of the cutting insert and the upper jaw of the holder and a lower contact part of the lower surface of the cutting insert and the lower jaw of the holder comprises a first concave-convex surface and a second concave-convex surface,
• the first concave-convex surface comprising a plurality of first convex parts and at least one first concave part that extend along the longitudinal direction of the holder,
• the second concave-convex surface comprising a plurality of second concave parts located correspondingly to the plurality of first convex parts and at least one second convex part located correspondingly to the at least one first concave part,
• wherein a distance d1 between tops of the first convex parts adjacent to each other among the plurality of first convex parts of the first concave-convex surface is smaller than a distance d2 between bottoms of the second concave parts adjacent to each other among the plurality of second concave parts of the second concave-convex surface which are located correspondingly to the first convex parts adjacent to each other in a sectional view perpendicular to the longitudinal direction of the holder, and
• wherein the distance d1 is a half or more of a width w1 of the first concave-convex surface, and the distance d2 is a half or more of a width w2 of the second concave-convex surface in the sectional view.

A cutting tool, comprising:

• a cutting insert comprising an upper surface, a lower surface and a cutting edge located on at least part of sides of the upper surface;
• and
• a holder comprising an upper jaw and a lower jaw that respectively fix the cutting insert from the upper surface and the lower surface at a front end part in a longitudinal direction thereof,
• wherein at least one of an upper contact part of the upper surface of the cutting insert and the upper jaw of the holder and a lower contact part of the lower surface of the cutting insert and the lower jaw of the holder comprises a first concave-convex surface and a second concave-convex surface,
• the first concave-convex surface comprising a plurality of first convex parts and at least one first concave part that extend along the longitudinal direction of the holder,
• the second concave-convex surface comprising a plurality of second concave parts located correspondingly to the plurality of first convex parts and at least one second convex part located correspondingly to the at least one first concave part,
• wherein a distance d1 between tops of the first convex parts adjacent to each other among the plurality of first convex parts of the first concave-convex surface is smaller than a distance d2 between bottoms of the second concave parts adjacent to each other among the plurality of second concave parts of the second concave-convex surface which are located correspondingly to the first convex parts adjacent to each other in a sectional view perpendicular to the longitudinal direction of the holder, and
• wherein, on a basis of a reference line L passing through a bottom of one first concave part of the at least one first concave part located between the first convex parts adjacent to each other and passing through a top of one second convex part of the at least one second convex part located correspondingly to the one first concave part, the first convex part located adjacent to the one first concave part is located closer to the reference line L than the second concave part located adjacent to the one second convex part in the sectional view.