Rotary tool and method for manufacturing cut product

A rotary tool, comprising:

• a main body having a circular columnar shape, the main body comprising a rotation axis and extending from a first end to a second end, wherein
• the main body comprises:
• a plurality of first flutes that are located on an outer periphery of the main body and run at a helix angle θ1 toward a rear side in a rotation direction of the rotation axis going along the main body toward the second end;
• a first cutting edge located on at least a part of a ridge line where the outer periphery of the main body intersects with the plurality of first flutes;
• a plurality of second flutes that are located on the outer periphery of the main body and run at a reverse helix angle θ2 toward a front side in the rotation direction of the rotation axis as going along the main body toward the second end, the plurality of second flutes intersecting with the plurality of first flutes;
• and
• a second cutting edge located on at least a part of a ridge line where the outer periphery of the main body intersects with the plurality of second flutes,
• wherein
• the reverse helix angle θ2 is larger than the helix angle θ1, and
• m≥5, m−n≥3;
• m and n are coprime numbers, where m is a number of the plurality of first flutes and n is a number of the plurality of second flutes;
• and
• a maximum width of each of the plurality of second flutes is smaller than a distance between first flutes adjacent to each other, in the rotation direction of the rotation axis, in the plurality of first flutes.