| 摘要 |
<p>In the fabrication of a drilling bit, particularly for rock drilling, by clamping a blank drill bit wth a solid head and placing an insert element, particularly of tungsten carbide, on the surface of the blank; each element is embedded in the blank in such a way that the part below the surface is surrounded by the material of the drill bit so as to retain it strongly and prevent any relative movement between the bit and the insert.</p> |
