| 摘要 |
A self feeding drill bit for making a smooth bore in a workpiece has a spiral land and flute with a leading end carrying a centered lead screw. The leading end of the bit has a cutter extending from said lead screw to the circumference of the bit. Diametrically opposed to the cutter is an inscriber formed as a curved blade by the periphery of the leading land. In use, the inscriber makes a smooth surfaced cut in the workpiece with the cutter removing the remainder of the workpiece within the scribed cut.
|
