To improve the production efficiency while performing the threading and the spot facing with one cutting tool without requiring an exchange of the tool.
This threading method and the spot facing working method are provided with a tool setting process, a lower hole working process for boring a screw lower hole in a work W with a drill blade 21 of a cutting tool 10, an offset process for offsetting a shaft of the cutting tool at a constant distance from a screw hole shaft 55, a threading process for rotating the shaft of the offset cutting tool around the screw hole shaft and while drawing it so as to thread a screw 56 with a threading blade, a process for inclining the work W at the predetermined angle α1, a process for inclining the cutting tool at an angle β1 so that the drill blade is set at a right angle against the screw hole shaft of the inclined work, and a spot facing working process for moving the cutting tool for precession so that the drill blade cuts an edge 58 of the screw hole inlet and while correcting the inclination of the work with the precession of the cutting tool so as to maintain the attitude of the screw hole shaft at a right angle against the drill blade for spot facing.
FUKUSHIMA HIROYUKI
NOMURA SUKEYUKI
ITO MASATOMI
ISHIBASHI TOMOMI
