Sumitomo Electric Hardmetal Corp.

Yuki Tsutsumi

Junya Okida

Christoph Zeiner

Shinya Nakata

Yusuke Matsuda

Masaaki Jindai

Hirofumi Tamanishi

Cutting tool

A cutting tool has a rake face and a flank face. The flank face is provided with a coolant supply hole. A ridgeline between the rake face and the flank face forms a cutting edge. An outer shape of the coolant supply hole in a cross section orthogonal to an axis includes a first portion facing the cutting edge, and a second portion opposite to the cutting edge when viewed from the first portion. The first portion has a concave portion extending toward the second portion. The concave portion is defined by a first side portion and a second side portion facing each other, and a bottom continuous with both the first side portion and the second side portion. In the cross section, an angle formed by a tangent of the first side portion and a tangent of the second side portion is not more than 160&#xb0;.

The negative land includes: a first region in which a space between the upper cutting edge and the lower cutting edge becomes wider toward the outer circumferential surface; and a second region which is continuous to the first region and in which the space becomes wider toward the rotation axis. In a cross section perpendicular to the rotation axis, the rake face includes a return face continuous to the outer circumferential surface, the return face being recessed opposite to a rotation direction of the drill. When a first boundary represents a boundary between the outer circumferential surface and the first region and a second boundary represents a boundary between the first region and the second region, a length of the first boundary is larger than a length of the second boundary in a direction parallel to the rotation axis. The second boundary is continuous to the return face.

Drill

Growing community of inventors

Itami, Japan

Yuki Tsutsumi