| 摘要 |
<p>An abrasive wheel for grinding a drill bit of the kind having hard metal inserts set into a head includes two circular flange portions and a circumferential profile groove between the flange portions corresponding to the end profile intended for drill bit insert. The flange portions and interposed profile groove are included in a first abrasive wheel body having a covering coating of abrasive agent such as diamond, adapted to grind hard metal. At least one other abrasive wheel body, is nonrotatable and concentrically connected to one flange portion of the first abrasive wheel body and, at a greater radial distance from the rotary shaft of the abrasive wheel than the adjacent flange portion of the first abrasive wheel body, has a circumferential end portion having a substantially round cross-sectional form and a coating of an abrasive agent, e.g. boron nitride, adapted to grind the material in the drill bit head.</p> |
