| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem of increasing cutting resistance to impede stable machining of a workpiece caused by deposition to a thinning cut face or the like when thinning a drill center part to improve centripetal property and to reduce cutting resistance in a drill for high efficiency machining of aluminum for boring aluminum or the like. SOLUTION: The drill for high efficiency machining of aluminum has a cutting edge at a drill groove tip part and is thinned at the center part viewed from the cutting edge side axial end. An intersection formed by the thinning cut face and a thinning heel face is provided in round shape, and the connection parts of a round part and the thinning heel face 5 is spaced over the drill center. The crossing width of a thinning cutting edge is reduced onto the drill center side to≥0.1% and≤50% of a drill diameter. COPYRIGHT: (C)2006,JPO&NCIPI
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