| 摘要 |
An insert for a percussion drill bit for drilling a hole in rock comprises a cylindrical portion and domed cutting surface. The domed cutting surface that comprises polycrystalline diamond has a tip radius that is between 0.3 and 0.4 times that of the diameter of the cylindrical portion. The diameter of the cylindrical portion is preferably greater than the gauge diameter of hole multiplied by 0.2.
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