| 摘要 |
PROBLEM TO BE SOLVED: To realize a drill for woodworking used by being mounted principally on an electric-powered drill and the like wherein a force for drawing the drill main body into a material to be perforated with a point screw is moderate. SOLUTION: A tapering off shaped point screw 2 is protrusively formed at a tip central part of the drill main body wherein a spiral cutting edge 1a is formed. A screw shape 6 comprising a thread ridge 6a and a thread root 6b is formed by a bandy spiral of a specific width to the point screw 2. Thereby, a drawing in force is less compared with a traditional wooden threaded point screw, and a drawing in force balanced with a cutting resistance is generated. For example, a woodworking drill wherein operations likely to open a hole not passing through by stopping perforation midway can be easily carried out, can be realized.
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