Abstract: A drill may include a body extending from a first end toward a second end, and the body may include an outer peripheral surface and a cutting edge. The cutting edge may include a first cutting edge and a second cutting edge. The second cutting edge may be positioned closer to the second end and the outer peripheral surface than the first cutting edge. The second cutting edge may include a first part, a second part and a third part. The second part may be positioned closer to the outer peripheral surface than the first part and may be positioned closer to the second end as close to the first part. The third part may be positioned closer to the first cutting edge than the first part and may be positioned closer to the second end as close to the first part.

Abstract: A drill may include a body extending from a first end toward a second end, and the body may include an outer peripheral surface and a cutting edge. The cutting edge may include a first cutting edge and a second cutting edge. The second cutting edge may be positioned closer to the second end and the outer peripheral surface than the first cutting edge. The second cutting edge may include a first part, a second part and a third part. The second part may be positioned closer to the outer peripheral surface than the first part and may be positioned closer to the second end as close to the first part. The third part may be positioned closer to the first cutting edge than the first part and may be positioned closer to the second end as close to the first part.

Abstract: A drill (1) based on an embodiment of the present invention is equipped with: a first chip discharge flute that is provided on an outer periphery of a drill body and spirally extends around a rotational axis from a first cutting edge toward a rear end of the drill body; a second chip discharge flute that is provided on the outer periphery of the drill body and spirally extends around the rotational axis from a second cutting edge toward the rear end of the drill body; and an auxiliary flute that is provided on the outer periphery of the drill body and extends along the second chip discharge flute on a front side in a rotating direction of the rotational axis, wherein a rear end of the second chip discharge flute extends further toward the rear end of the drill body than the first chip discharge flute.

Abstract: A drill (1) based on an embodiment of the present invention is equipped with: a first chip discharge flute that is provided on an outer periphery of a drill body and spirally extends around a rotational axis from a first cutting edge toward a rear end of the drill body; a second chip discharge flute that is provided on the outer periphery of the drill body and spirally extends around the rotational axis from a second cutting edge toward the rear end of the drill body; and an auxiliary flute that is provided on the outer periphery of the drill body and extends along the second chip discharge flute on a front side in a rotating direction of the rotational axis, wherein a rear end of the second chip discharge flute extends further toward the rear end of the drill body than the first chip discharge flute.