A machining tool is a machining tool rotated about an axis and is provided with a machining blade portion having a rake face and a machining blade, wherein in a case where the rake face faces and is parallel to an virtual plane including the axis, the rake face is arranged at a position shifted from the virtual plane in the direction opposite to the rotational direction of the machining tool.

A reamer includes a core, a plurality of outer-circumference cutting edges provided on an outer circumference of the core and made of a hard tool material, and a margin provided on a rear side of each the plurality of outer-circumference cutting edges in a rotational direction. A distance from an axis of rotation to a position of a center of gravity of the reamer is greater than 0.01 mm and not greater than 0.5 mm.

A machining tool is a machining tool rotated about an axis and is provided with a machining blade portion having a rake face and a machining blade, wherein in a case where the rake face faces and is parallel to an virtual plane including the axis, the rake face is arranged at a position shifted from the virtual plane in the direction opposite to the rotational direction of the machining tool.

A reamer includes a core, a plurality of outer-circumference cutting edges provided on an outer circumference of the core and made of a hard tool material, and a margin provided on a rear side of each the plurality of outer-circumference cutting edges in a rotational direction. A distance from an axis of rotation to a position of a center of gravity of the reamer is greater than 0.01 mm and not greater than 0.5 mm.

A rotary cutting tool includes a first cutting blade, a second cutting blade, a third cutting blade, a fourth cutting blade, and a fifth cutting blade on a circumference, in which a rotation angle from the first cutting blade to the second cutting blade is 60?1?, a rotation angle from the second cutting blade to the third cutting blade is 75?1?, a rotation angle from the third cutting blade to the fourth cutting blade is 60?1?, a rotation angle from the fourth cutting blade to the fifth cutting blade is 75?1?, and a rotation angle from the fifth cutting blade to the first cutting blade is 90?1?.

In one aspect, reamers having radially extending flutes are described herein. A reamer described herein comprises a cutting portion including a plurality of cutting teeth separated by flutes, the cutting teeth defining an outer diameter of the cutting portion and the flutes extending radially to define an inner diameter of the cutting portion.

A reaming tool, having a rotationally drivable main body (16) and at least one cutting body (18) fastened thereto. The at least one cutting body has at least one reaming blade (26) at the edge of a rake face (28). A chip-forming step (32) and/or chip-breaking elements (34) are formed in the rake face (28) and the reaming blade (26) has a ground cutting edge (40, 42, 44).