Hilti Aktiengessellschaft

Berthold Aumueller

Peter Gstach

A thread-tapping screw () has a thread () extending, starting from the screw shaft free end (), at least along a portion of the shaft length and a height of which constantly decreasing toward the free end () of the shaft (), and a plurality of cutting bodies () formed of a material having a greater hardness than hardness of the thread (), located in recesses () formed in the thread () and opening radially outwardly and having, respectively, a radial outer profile () projecting, at least partially, beyond the thread and a height (A, B, C, D, E) of which decreases toward the free end () of the shaft () stepwise.

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Grafenwöhr, Germany

Berthold Aumueller