| 摘要 |
PROBLEM TO BE SOLVED: To provide a new burnishing drill having machining accuracy equal to or more than that of a conventional burnishing drill and remarkably hardly generating a quality defect such as a galling defect. SOLUTION: This burnishing drill is provided with a plurality of cutting edge parts 22, a plurality of burnishing edge parts 23 provided among the plurality of cutting edge parts 22, a plurality of land parts 24 for forming each outer peripheral edge part in the plurality of cutting edge parts 22 and the plurality of burnishing edge parts 23, a chip discharge groove 25 formed in a region among front sides of the cutting edge parts 22 and rear sides of the land parts 24 formed in the burnishing edge parts 23, and a drill wall surface 26 formed among the rear sides of the land parts 24 formed in the cutting edge parts 22 and the front sides of the burnishing edge parts 23. A chip discharge groove 30 extended in an axis direction in the vicinities of the front sides of the burnishing edge parts 23 in a drill rotating direction shown by a code A is formed on the drill wall surface 26. COPYRIGHT: (C)2007,JPO&INPIT
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