| 摘要 |
In a counterboring tool for drilling in the solid and having a shank and a cutting part, a greater cutting capacity as well as improved dimensional accuracy of the holes produced are achieved by the cutting part being cylindrical and having at least three spiral flutes with in each case a secondary cutting edge, and on its end face, in accordance with the number of secondary cutting edges, at least three symmetrically arranged main cutting edges and a centring point.
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