Twist drill
AssigneeMitsubishi Materials Corporation
InventorsSueji Takaya, Kazuo Takasaki, Kazuaki Tone
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Abstract
A twist drill is disclosed. The twist drill comprises a substantially cylindrical tool body having a rotational axis therethrough, a front portion, a rear portion, a plurality of web thickness, a front flank face, a plurality of flutes formed on an outer peripheral surface thereof and extending to the front flank face, and a land disposed between a pair of the flutes. The flute has a wall portion facing toward the rotational direction of the tool body. A cutting edge is formed at an intersection between the wall portion of the flute and the front flank face. The web thickness at the rear portion of the tool body is smaller than the web thickness at the front portion of the tool body.
Claims10
A twist drill comprising:
- a substantially cylindrical tool body having a rotational axis therethrough, a front portion, a rear portion, a front flank face, a plurality of web thicknesses, a plurality of flutes formed on an outer peripheral surface thereof and extending to the front flank face, and a land disposed between a pair of the flutes, said flute having a wall portion facing toward the rotational direction of the tool body;
- and
- a cutting edge formed at an intersection between said wall portion for the flute and said front flank face;
- said flute consisting of a spiral portion opening to the front flank face and a straight portion extending from the rear end of said spiral portion toward the rear portion of the tool body and extend in parallel to the axis of said body, and the web thickness at said straight portion being less than the web thickness at said spiral portion.
Dependencies are inferred from the claim text.