| 摘要 |
A self-drilling and self-tapping screw with a compound flute configuration having a straight portion including at least part of the cutting edge and a curved portion defining the drag surface. Generally convex point configurations having uniformly radiused heels or, alternatively, heels formed by two planar surfaces intersecting to enclose an obtuse angle less than 180 degrees are also disclosed. Fluting cutters and pointing cutters for making this screw as well as a general description of the method of making the screw have been set forth in the instant application.
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