| 摘要 |
PROBLEM TO BE SOLVED: To provide a drill for deep hole boring with long service life capable of carrying out high efficient boring by inhibiting damage of a tool caused by clogging of a chip. SOLUTION: A converse web taper linearly made small as thickness W of the web is advanced to a shank 12 side is provided on a whole area from a tip end of the drill to a groove cut-up part and a surface of a body 14 is coated with a hard film. Surface roughness (the maximum height Ry) of a chip discharge groove 18 is made to 3μm or less by applying polishing treatment to the hard film. Therefore, chip discharge performance is enhanced to inhibit damage of the tool caused by clogging of the chip, the high efficient machining becomes possible and the service life is enhanced. For example, even when the deep hole having depth dimension of 15 times or more the diameter D of the drill is cut/machined at the high efficient machining with cutting speed V of 80 m/min or more and feed per revolution f of 0.10 mm/rev or more, the damage of the tool caused by clogging of the chip is inhibited and the service life (the number of machining holes) satisfied on practical use is obtained. COPYRIGHT: (C)2004,JPO |
