摘要 |
A cutting tool, a drill for instance, having a drill body and a cutting portion. The cutting portion comprises a central cutting insert and two peripheral cutting inserts. A cutting edge extends along the three inserts. The inserts comprise surfaces for facilitating a tight connection between the parts of the cutting edge. The peripheral inserts consist of a material of greater hardness than the material in the central insert, and therefore the cutting edge is adapted for the varying cutting speeds in the radial direction of the tool. |