Hilti Aktiengesellschaft

Albert Loichinger

Michael Baumgartner

Sven Matthiesen

A self-drilling screw () has a first cutting edge () provided exclusively in a radially inner region of the drilling tip (), extending at a first acute angle (&#x3b1;) to the longitudinal axis (L), and a second cutting edge () provided in radially outer region of the drilling tip () and extending at a second acute angle (&#x3b1;) to the longitudinal axis (L), with a first enveloping conical circumferential surface (A) which is defined by the first cutting edge () corresponding, with a maximum deviation of +/&#x2212;10%, to a second enveloping conical circumferential surface (A) defined by the second cutting edge (), and with the first acute angle (&#x3b1;) corresponding, with a maximum deviation of +/&#x2212;5&#xb0;, to the second acute angle (&#x3b1;).

Self-drilling screw

A self-drilling screw () has a thread-carrying shaft (), a head () provided at one of its ends, and a drilling tip () provided at another of its ends, opposite the one end thereof, with the drilling tip () having first and second cutting edges () and first and second chip channels () associated with the first and second cutting edges (), respectively, beginning at first and second start points () at the free end () of the drilling tip (), and located on opposite first and second sides of the drilling tip (), with the first and second start points () being spaced from the center (Z) of the drilling tip () by a mean distance (X) corresponding to from 0.01 to 0.15 of the drilling tip diameter (D), and being spaced from each other by a maximum distance (Y) corresponding to from 0 to 0.8 of the mean distance (X).

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Sax, Switzerland

Albert Loichinger