| 摘要 |
PURPOSE: A rotary drill tool and a base body thereof are provided to effectively discharge chips as a short front segment with a thin chip flute and long rear segment with a thick flute are formed. CONSTITUTION: A rotary drill tool comprises a base body(1) and an insert upper part(2). The insert upper part is connected to the base body. The axial extended portion of the insert upper part is formed between a front insert end portion and a rear connection end portion along a longitudinal axis(4). The cutting diameter of the front insert end portion restricts a cutting circle with a vertical shaft line. The base body comprises the axial extended portion and one or more chip flutes(9). The axial extended portion is formed between a front connection end portion and a rear fixing end portion along the vertical shaft line.
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