Patent attributes
A drill according to a non-limiting aspect may have a body, a cutting edge, a rake face, and a groove. The cutting edge may have a curved chisel edge, a pair of first cutting edges, and a pair of second cutting edges. The second cutting edge may have a first portion extending from the chisel edge and a second portion extending from the first portion toward the first cutting edge. The rake face may have a first region extending from the first portion and a second region extending from the second portion. A first rake angle of the first region may be zero or a negative value. A second rake angle of the second region may be a negative value. An absolute value of the second rake angle may be greater than an absolute value of the first rake angle.
