| 摘要 |
A self-boring screw (2) having a boring section (6) attached to the free end of the screw shaft (4), two vanes (12) radially protruding from the boring section, the edges of the vanes facing toward the boring tip (8) of the boring section (6) being configured as boring blades (13). The boring section (6) includes a chip discharge zone (14) that is configured such that the edges of the vanes (12) facing toward the boring tip (8) forms a cutting point (S) with a boring radius (16), the cutting point having a distance (A) to the screw shaft (4) that is at least ⅔ of the cutting edge length of the bore tip (8). The chip discharge zone (14) makes it possible that the chips produced by the boring blade (10) at the boring tip (8) can be discharged freely and without buildup. The material cut by the boring blade (10) is conveyed as chipped material away from the boring tip (8) in the direction of the cutting point (S) at a lower vane connection (15) as a result of the rotational motion of the screw (2), thus ensuring unhindered chip discharge. It is possible to compress the chips to be discharged to a maximum of ⅔ of the cross section occurring after the cut. This ensures that even critically sized chips are removed without blocking the discharge of chips from the area of the boring section (6).
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