摘要 |
A helically fluted twist drill apparatus in which offset, opposed veins of sintered abrasive particulate, such as diamond, are embedded within a drill blank made of a less abrasive material such as carbide. The non-aligned veins of abrasive material, in one embodiment, themselves intersect through juxtapositioning adjacent the point and web of the drill, and in another embodiment, rely upon the interpositioning of a third intermediate vein which, in turn, intersects at least part of both the first and second nonintersecting veins, to describe a more economical and effective highly abrasive material region at the drill point and web locations.
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