Cutting tool

A cutting tool comprising:

• a main body portion composed of a cemented carbide;
• and
• a front end portion composed of one of a binderless cubic boron nitride polycrystal, a binderless diamond polycrystal and a diamond single crystal, the front end portion being joined to the main body portion, wherein
• in an axial direction along a rotation axis of the main body portion, the main body portion has a first end and a second end opposite to the first end, the front end portion has a neck portion and an edge portion, the neck portion protruding from the second end along the axial direction, the edge portion being continuous to the neck portion, the edge portion being located at a location distant away from the second end relative to the neck portion in the axial direction,
• in the axial direction, the neck portion has a third end on the edge portion side and a fourth end opposite to the third end,
• the edge portion includes a cutting edge at an outer circumference of the edge portion,
• at the fourth end, a cross sectional area of the neck portion in a cross section orthogonal to the axial direction is larger than an area of a circumscribed circle of the cutting edge, the circumscribed circle centering on the rotation axis when seen in a front view from the front end portion side along the axial direction, and
• a length of the front end portion in the axial direction is larger than a diameter of the circumscribed circle.