Patent 7621699 was granted and assigned to Bosch (company) on November, 2009 by the United States Patent and Trademark Office.
A rotary tool accessory for shaping hard, brittle material is disclosed. In one embodiment, a work portion includes a first flute extending from one end portion of the work portion toward the other end of the work portion and a first land adjacent to the first flute. A first leading edge is located between the first flute and the first land and at least one recess extends from the first leading edge into the first land. An abrasive material is located at the surface of the first leading edge.