| 摘要 |
PROBLEM TO BE SOLVED: To provide a drill structure capable of achieving superior drill performance by increasing the rigidity of a drill bit, a chip storage space, a chip discharge force, and the precision of a drill.SOLUTION: In a drill structure, two chip discharge channels are spirally arranged in a body. The two chip discharge channels are in a gradual junction state from a drill top end toward a drill handle or the two chip discharge channels are in an overlapped state from the drill top end toward the drill handle. The two chip discharge channels are provided with a first depth and a second depth, respectively, and a rate of a depth change of the first depth is different from that of the second depth in a direction which is from the drill top end toward the drill handle. The drill structure has high drill performance. |
