主权项 |
1. A drill, comprising:
a cutting tip; and a holder, the cutting tip comprising
a first cutting edge and a second cutting edge located away from each other at a front end portion of the cutting tip,a first flute and a second flute which are respectively continuous with the first cutting edge and the second cutting edge on a front side in a rotation direction, and extend toward a rear end portion side of the cutting tip,a first side surface and a second side surface which are respectively continuous with the first flute and the second flute on the front side in the rotation direction, and extend toward the front side in the rotation direction,a first constraining surface and a second constraining surface which are respectively continuous with the first side surface and the second side surface on the front side in the rotation direction, and extend in a tilt direction with respect to the rotation direction, anda bottom surface located on the rear end portion, and the holder being located on the rear end portion side of the cutting tip, the holder comprising
a mounting surface being in contact with the bottom surface,a first contact surface and a second contact surface being respectively in contact with the first side surface and the second side surface, anda first hold surface and a second hold surface being respectively in contact with the first constraining surface and the second constraining surface, wherein the first side surface and the second side surface are asymmetric with respect to a central axis, and the first constraining surface and the second constraining surface are point symmetric with respect to the central axis in a front end view. |