| 摘要 |
<p>A cutting element, for a rotary drill bit, comprises a tablet (22) having a front face, a rear face and a peripheral edge, at least the front face of the table being provided by a layer of superhard material, such as polycrystalline diamond. The peripheral edge of the tablet is formed with one or more re-entrant portions (23, 24) so as to define projecting cutting portions (25, 26, 27) to the sides of the re-entrant portions. The element may be cut from a blank which is initially circular.</p> |
