| 摘要 |
A drill bit comprising a pointed end and a bit shaft. A dust suction passage is formed in the bit shaft. A hole, which has an opening in the pointed end or in an area near the front end of the bit shaft, is formed. The bit shaft has a first section that has a core and ribs. The core extends in the axial direction and is thinner than the pointed end. The ribs extend outward in the radial direction from the side surface of the core and extend over the entire length of the first section. The dust suction passage bores through the core in the axial direction. |
