| 摘要 |
A rotatable cutting tool for impacting and fragmenting a substrate. The tool has a tool body containing a valve seat in the forward end thereof wherein a hard insert affixes to the tool body within the valve seat. The hard insert comprises an integral tip segment and an integral axially rearward segment joined to the tip segment by an integral mediate segment. A trio of generally vertically disposed flanges project radially outward from the mediate segment. The flanges are integral with the mediate portion. Each flange presents at least one side surface. During operation, the substrate fragments impinge against the side surface to urge the tool to rotate about its central longitudinal axis. |
