THROW AWAY TYPE DRILL TIP AND THROW AWAY TYPE DRILL

摘要

PROBLEM TO BE SOLVED: To provide a drill tip and a drill improving a surface roughness of the inner peripheral surface of a machined hole, improving a cutting blade life, and stabilizing the hole diameter of the machined hole, when drilling under a high feeding condition.;SOLUTION: In a drill tip of the present invention, one of the polygonal faces of a polygonal flat plate tip main body is selected to be a rake face, and cutting edges are formed in a side ridge part of the polygonal face. In the drill tip, an outer peripheral edge (8) is attached to the outer peripheral side of the tip end part of the drill main body (1), and a linear flat drag (11) is formed in a direction of an axial line (O) of the drill main body (1), adjacently to the corner part (10) arranged in a diameter outside direction of the drill main body (1) viewed from the direction opposed to the rake face, when attached to the drill main body (1) as the outer peripheral edge (8).;COPYRIGHT: (C)2005,JPO&NCIPI