Patent 6981496 was granted and assigned to Hilti on January, 2006 by the United States Patent and Trademark Office.
A point chisel for use with a power tool includes an elongate stem (1) having, at its power tool side a shank (2) for securing the chisel in the power tool and, at its workpiece side, a useful region (3) having its outer diameter (H) tapering toward its workpiece end and having a cross-section (5) formed as a concave polygon by a plurality of axial grooves (4) extending radially toward a core diameter (K) that likewise tapers toward the workpiece side end of the useful region (3).