Abstract: A rotating tool according to one aspect includes a body that extends from a first end to a second end, and the body includes a second helical cutting edge, a second helical flute, a first helical cutting edge, and a first helical flute. The body further includes a reversely-helical cutting edge and a reversely-helical flute from the second helical flute. The reversely-helical cutting edge and the reversely-helical flute are helical reversely to the second helical flute from the second helical flute to the second end, and the reversely-helical flute extends along the reversely-helical cutting edge. The reversely-helical cutting edge is positioned intersecting with an extended line of a trace of the first helical cutting edge and not intersecting with an extended line of a trace of the second helical cutting edge.

Abstract: In an aspect, a rotating tool includes a main body having a rod shape and extending along a rotation axis. The main body includes a first end, a second end, a twisted cutting edge located at a side of the first end, a twisted flute, a reverse twisted cutting edge located closer to the second end than the twisted cutting edge, and a reverse twisted flute. The reverse twisted flute is connected to the twisted flute. The twisted cutting edge includes a first part having a length from the rotation axis decreasing as approaching toward the second end.

Abstract: A rotating tool according to one aspect includes a body that extends from a first end to a second end, and the body includes a second helical cutting edge, a second helical flute, a first helical cutting edge, and a first helical flute. The body further includes a reversely-helical cutting edge and a reversely-helical flute from the second helical flute. The reversely-helical cutting edge and the reversely-helical flute are helical reversely to the second helical flute from the second helical flute to the second end, and the reversely-helical flute extends along the reversely-helical cutting edge. The reversely-helical cutting edge is positioned intersecting with an extended line of a trace of the first helical cutting edge and not intersecting with an extended line of a trace of the second helical cutting edge.

Abstract: An end mill includes an end mill body having a bar-shape extending along a rotation axis and including a first end and a second end, a side surface, a first end cutting edge, a second end cutting edge, a first peripheral cutting edge extending from the first end cutting edge, and a second peripheral cutting edge extending from the second end cutting edge. In which, L2 is smaller than L1, where L1 is a distance from the rotation axis to the first peripheral cutting edge, and L2 is a distance from the rotation axis to the second peripheral cutting edge in a cross section orthogonal to the rotation axis. And ?2 is greater than ?1, where ?1 is a rake angle of the first peripheral cutting edge, and ?2 is a rake angle of the second peripheral cutting edge.

Abstract: In an aspect, a rotating tool includes a main body having a rod shape and extending along a rotation axis. The main body includes a first end, a second end, a twisted cutting edge located at a side of the first end, a twisted flute, a reverse twisted cutting edge located closer to the second end than the twisted cutting edge, and a reverse twisted flute. The reverse twisted flute is connected to the twisted flute. The twisted cutting edge includes a first part having a length from the rotation axis decreasing as approaching toward the second end.

Abstract: An end mill includes an end mill body having a bar-shape extending along a rotation axis and including a first end and a second end, a side surface, a first end cutting edge, a second end cutting edge, a first peripheral cutting edge extending from the first end cutting edge, and a second peripheral cutting edge extending from the second end cutting edge. In which, L2 is smaller than L1, where L1 is a distance from the rotation axis to the first peripheral cutting edge, and L2 is a distance from the rotation axis to the second peripheral cutting edge in a cross section orthogonal to the rotation axis. And ?2 is greater than ?1, where ?1 is a rake angle of the first peripheral cutting edge, and ?2 is a rake angle of the second peripheral cutting edge.