| 摘要 |
A threaded element for forming a threaded profile in the wall of a bore formed in a material and for insertion into the bore so as to reinforce the bore. The threaded element includes a cylindrical stem having an external thread having a plurality of separate tapping lobes for cutting the threaded profile in the wall of the bore. The stem has an unthreaded radius smaller than the unthreaded radius of the bore and a threaded radius greater than the unthreaded radius of the bore. A recess is defined between each adjacent pair of tapping lobes. Each tapping lobe is defined by two cutting arcs formed at its opposite ends and a convex escape-gap arc is located intermediate the two cutting arcs. Each cutting arc has a convex configuration relative to the center of the stem, and the apex of each of the cutting arcs defines the maximum thread radius of the threaded profile, as measured from the center of the stem. Each escape-gap arc is convex and has an escape radius that is smaller than the aforementioned maximum thread radius but greater than the minimum thread radius of the threaded profile, as measured from the center of the stem.
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