Hilti Aktiengesellschaft

Sven Dietze

Jan Allaart

Rene Ortler

Thorsten Ebert

A fastening element has a head (), a stem () adjoining the head) and having a tip at its end remote from the head (), a first bullet-shaped section () extending from the tip () in a direction of the head (), and a thread profile () provided on the stem () and having, on the second section (), a constant steep gradient with a lead angle (&#x3b2;) from&#xb0; to&#xb0; and, on the first section (), a gradient that increases from the lead angle (&#x3b2;) of the second section () toward the tip (), with a lead angle (&#x3b2;) at a half of a length between the tip () and the end () of the first section () remote from the tip () amounting to at least&#xb0;.

Fastening element

A fastening element which has a core () of a relatively hard, carburized steel and a ferritic rim zone () of a less hard, low-carbon steel, includes a stem (), a head () provided at one end of the stem (), a tip () provided at an opposite end of the stem (), and a transition region () extending between the stem () and the tip () and in which a thickness () of the ferritic rim zone () gradually diminishes from the stem () in a direction toward the tip () to a nill value (), so that the tip () is free from the ferritic rim zone ().

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Feldkirch, Austria

Sven Dietze