PURPOSE: To cool chips produced from the cutting point of an addendum and to guide the chips to an inner chip guiding surface by a method wherein a straight-line part having a length of 2.0mm or less from the addendum is formed on the face side of the acute angular addendum of each saw tooth.

CONSTITUTION: Chips produced at the cutting point of an addendum 13 flow along a first straight-line part 15. Since the chips are apt to curl owing to generated heat but the chips are difficult to curl when the straight-line part 15 is too long, the straight-line part 15 is set to a value lower than 2.0mm. The chips are guided to a chip induction surface 17 forming a guide for curling. The chip induction surface 17 connected to the straight-line part 15 is formed in a recessed arcuate shape with a radius of 0.5-3.0mm and the inner end of the chip induction surface is protruded frontward in a cutting direction from the addendum 13 by a distance of 1/2 or less of the radius. The chips fed from the straight-line part 15 are guided in a manner to arcurately roll them in not by material quality but by a recessed arcuate surface to effectively generate a curl. This constitution causes effective production of chips most of which are curled during processing of chips.