Drill
AssigneeBic Tool Co., Ltd.
InventorsKoichi ARAI, Giichi ARAI, Katsuyo KIMURA, Satoshi TESHIMA
Life of this patent
Estimating the term…
Abstract
The problem to be solved is to provide a drill that is difficult to break and has a good cutting ability. The drill according to the present invention comprises: a first and a second cutting edge formed symmetrically with respect to a rotation axis; a first and a second relief surface formed symmetrically with respect to the rotation axis on back surfaces of the first and the second cutting edge, respectively; one chip-discharging groove formed from one of the first and the second cutting edge toward an outer peripheral side; and one or more arc-shaped grooves formed from another of the first and the second cutting edge toward the outer peripheral side.
Claims6
A drill comprising:
- a first and a second cutting edge formed symmetrically with respect to a rotation axis;
- a first and a second relief surface formed symmetrically with respect to the rotation axis on back surfaces of the first and the second cutting edge, respectively;
- one chip-discharging groove formed from one of the first and the second cutting edge toward an outer peripheral side;
- and
- one or more arc-shaped grooves formed from another of the first and the second cutting edge toward the outer peripheral side.
Dependencies are inferred from the claim text.