Hilti Aktiengesellschaft

Hilti Aktiengsellschaft

Hilti Akitengesellschaft

Corinna Achleitner

Guenter Domani

Carsten Peters

Simon Oppeneiger

Falk Rosenkranz

Mark Winkler

Franz Huber

Juergen Gebhard

Georg Oberndorfer

Carl Hoffmann

Andreas Vorhauer

Juergen Gahn

Martin Pleil

Isaiah Freerksen

Ralf Zitzmann

Berthold Aumueller

Mirco Fleige

Jürgen Gebhard

Jürgen Gahn

Berthold Aumüller

A method for producing a twist drill has the following steps. A blank is shaped to form a semi-finished product. The semi-finished product is formed from a core, coaxial with the drill axis, having a radius and a number of webs, arranged on the core, having a height. The semi-finished product has a constant cross section along the drill axis. The webs have a first portion which adjoins the core and in which a width of the web remains constant or decreases in the circumferential direction with increasing radial distance from the drill axis. The webs have a second portion which adjoins the first portion and in which the width of the web increases in the circumferential direction with increasing radial distance from the drill axis. The webs of the semi-finished product are shaped into helical segments using a plurality of rolling tools that annularly enclose the semi-finished product and roll on the webs along the drill axis. The rolling tools have teeth that are inclined with respect to the drill axis. A height of the helical segments is less than the height the webs. Helical segments formed from adjacent webs are in contact with one another in a closing fold. The invention also relates to a twist drill.

Twist drill and production method

The twist drill () has a drilling head (), a continuous two-flute, three-flute to six-flute helix () and an insertion end () that are arranged consecutively on a drill axis (). The helix () has a radial outer dimension () that varies periodically two, three to six times per revolution around the drill axis (). The invention also relates to a production method for such a drill.

A rolling die for forming a screw thread on a screw blank is disclosed. The rolling die has a plurality of grooves, where the grooves each have two flanks as seen in cross-section. At least a portion of each of the grooves has a forming area in which the size of a profile angle enclosed by the flanks decreases continuously along the grooves.

Rolling die

In the case of a screw having at least one thread () that is formed by a rolling process, especially a flat-die rolling process, whereby the thread () consists of two ridges of material () which are shaped from a blank () by means of cold-forming during the rolling process in such a way that the thread has a closing crease () where the ridges of material () meet each other, it is provided that the closing crease () is situated in the area of a flank () of the thread ().

Screw method for forming a screw thread

A method for manufacturing a thread-forming screw having a shank and a thread formed in one piece with the shank and region-wise circumferentially arranged on the shank, is disclosed. After the formation of the thread on the shank, a plurality of recesses is subsequently stamped into the thread. Then, a plurality of compact cutting elements is welded into the recesses in the thread, where the cutting elements are made of a hard material and have a hardness greater than the hardness of the thread. Additionally, a stamping device for carrying out the method is also disclosed.

Method for manufacturing a thread-forming screw

A self-tapping screw is disclosed. The screw includes a shaft which has a first end and an opposing second end with a load-engaging structure, and a thread that extends at least in sections over the length of the shaft. Several wear indicators are provided on the thread. Identifiers are provided on the screw for identifying the wear indicators.

Self-tapping screw

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Bludenz, Austria

Corinna Achleitner