Patent ID: 6238151
Filing Date: 2001-05-29
Classification: B23B,B23C,Y10S,Y10T

Abstract:
A drilling tool comprising:a substantially columnar tool body rotatable about an axis;a chip discharge groove formed in an outer periphery of the tool body and opened at a distal end face of the tool body;a cutting edge having a rake face and extending from an end adjacent to the axis toward the outer periphery of the tool provided along a crossing ridge between a wall surface of the chip discharge groove facing in a circumferential direction of the tool and the distal end face; anda concave surface of the end of the tool body rising in the circumferential direction of the tool with respect to the rake face of the cutting edge, the concave surface forming a concave curve advancing toward the distal end face of the tool in the circumferential direction of the tool, the concave surface being formed between the crossing ridge and the distal end face,wherein the concave surface is connected to the rake face via a step portion of 1 mm or less.