| 摘要 |
PROBLEM TO BE SOLVED: To provide a cutting tool to minimize 'burr' produced at the time of drilling a plate material with a drill. SOLUTION: This drill is provided with two kinds of blades of a drilling blade made of a right hand blade and a finishing blade made of a left hand blade coaxially between a blade edge 11 and a shank 12. Additionally, an outside diameter of the drilling blade arranged on the side of the blade edge 11 out of the two kinds of blades is formed slightly smaller in diameter than an outside diameter of the finishing blade arranged on the shank side, and it is possible to remove 'burr' produced by the drilling blade by the finishing blade.
|
