| 摘要 |
PROBLEM TO BE SOLVED: To reduce the cost of a drill which is constituted by fixing a blade member and a shank which are separate from each other. SOLUTION: In a blade member 10, a cutting blade 24 is formed on a tip part of a cemented carbide flat plate. The cross line of a flank 22 and a side 20 is the cutting blade 24, and as the chip can be discharged through a side space of the side 20, a chip discharge groove extended in the axial direction need not be formed. In a shank 12, a slot groove 32 is formed in the axial direction from a chip surface 30 of a round bar made of special steel, and a base end part 16 of the blade member 10 is engaged in the slot groove 32, and brazed thereto. In addition, a coolant hole 36 having a large diameter hole part 38 is formed in the shank 12. Since the drill is simple in structure, it can be manufactured at low cost. |
