Die Erfindung betrifft ein Verfahren zum Herstellen eines eine Beschichtung (6) und eine Schraubverbindung (10) aufweisenden Werkstücks (1) mit den Schritten: Bereitstellen des Werkstücks (1) und einer der Schraubverbindung (10) angehörenden Schraube oder Schraubenmutter, Herstellen einer Gewindebohrung (2) oder eines Gewindebolzens an dem Werkstück (1) für ein Zusammenwirken mit der Schraube oder der Schraubenmutter, und Aufbringen der Beschichtung (6) auf zumindest einen Bereich der Oberfläche (4,5) des Werkstücks. Dabei ist vorgesehen, die folgenden Schritte in nachstehender Abfolge durchzuführen: Herstellen einer Vertiefung (9), insbesondere einer Bohrung, oder eines Vorsprungs, insbesondere eines Bolzens, an dem Werkstück (1), Aufbringen der Beschichtung (6) auf das Werkstück (1), wobei die Oberfläche der Vertiefung (9) oder des Vorsprungs zumindest bereichsweise mitbeschichtet wird, und Ausbilden der Gewindebohrung (2) durch Eindrehen der Schraube in die beschichtete Vertiefung (9), wobei als Schraube eine gewindeschneidende Schraube verwendet wird, oder Ausbilden des Gewindebolzens durch Aufdrehen der Schraubenmutter auf den beschichteten Vorsprung, wobei als Schraubenmutter eine gewindeschneidende Schraubenmutter verwendet wird.

The object of the present invention is to prevent the encroaching and the seizure between the bolt and the female screw caused by an oblique screwing of the bolt into the female screw when the bolt and the female screw are fastened together. Another object of the present invention is to manufacture the bolt in a low cost, by using said bolt, the encroaching and the seizure between the bolt and the female screw caused by a oblique screwing of the bolt into the female screw are certainly prevented. Said objects may be attained by a bolt consisting of a column part and a polygonal pillar part extending from an end of said column part wherein a complete thread is formed on said column part and a screw blade continuing to said complete thread is formed on said polygonal pillar part.

A threaded fastener (10) has an eccentric tip (16) with a smooth portion (26), a threaded portion (28) and a cleaning recess (30) formed into the threaded portion (28) of the tip (16). The recess (30) nd tip (16) are formed in the heading operation prior to rolling the threads onto the shank (14) which provides better thread quality.

An earthing nut 11 according to the present invention, in which a fastening force is great and a conduction state can be reliably achieved with respect to a bolt 33, includes a screw hole 22 that is engaged with the bolt 33 in which screw threads 21 are formed at a pitch P. In all screw threads 21 provided in the screw hole 22, a pitch Pn of the screw thread 21 is greater than the pitch P of the screw thread 21 of the bolt 33, and an angle θ [degrees] of the screw thread 21 is formed to be greater than 60 degrees. In a portion of the screw hole 22 in an axial direction, a cut-out 25 is provided extending in the axial direction, and an end surface of the screw thread 21 facing the cut-out 25 forms a cutting edge 26.

An earth bolt is capable of achieving electrical connection and watertight sealing and of holding fragment of a coating so that the fragments of coating may not be scattered. The earth bolt can be electrically connected to a member coated with an insulating film. The earth bolt has a head and a threaded body. The head is provided on its bearing surface with an annular ridge protruding from the bearing surface of the head so as to coaxially surround the threaded body and capable of scraping off the insulating film.

A threaded bolt (1) having a shank (2) of basic cylindrical form and with a root end (3) and a head end (4) is provided with a spiral-shaped external thread (11), which has at least one principal flight (12) and in the vicinity of the root end (3) has at least one lead-in flight (13), adjoined by the principal flight (12), where the lead-in flight (13) has a lead-in surface which differs from the principal flight (12) and is formed in order to come into crossing-free engagement with flights of a complementary internal thread of an element. The lead-in flight (13) and the principal flight (12) are interrupted by at least one groove (15), which extends in the longitudinal direction of the shank (2) in order to form a free space for the accommodation of lacquer residues. The flights (12, 13) and the grooves (15) are primary shaped by rolling.

A threaded bolt (1) having a shank (2) of basic cylindrical form and with a root end (3) and a head end (4) is provided with a spiral-shaped external thread (11), which has at least one principal flight (12) and in the vicinity of the root end (3) has at least one lead-in flight (13), adjoined by the principal flight (12), where the lead-in flight (13) has a lead-in surface which differs from the principal flight (12) and is formed in order to come into crossing-free engagement with flights of a complementary internal thread of an element. The lead-in flight (13) and the principal flight (12) are interrupted by at least one groove (15), which extends in the longitudinal direction of the shank (2) in order to form a free space for the accommodation of lacquer residues. The flights (12, 13) and the grooves (15) are primary shaped by rolling.

The present invention provides a male screw part (1) comprising a head (4) and a shank portion (5) extended from the head and formed with screw threads (7), and being adapted to be screwed into a mating female screw part (40), wherein the screw threads disposed in the vicinity of a tip end of the shank portion in a direction of screwing are formed with at least one notch (12) in a heightwise direction thereof, the notch having edges intersecting with a ridgeline of the screw threads, and wherein a root diameter of the notch (X) is larger than an inner diameter of the female screw part (Y).

The present invention provides a male screw part comprising a head and a shank portion extended from the head and formed with screw threads, and being adapted to be screwed into a mating female screw part, wherein the screw threads disposed in the vicinity of a tip end of the shank portion in a direction of screwing are formed with at least one notch in a heightwise direction thereof, the notch having edges intersecting with a ridgeline of the screw threads, and wherein a root diameter of the notch is larger than an inner diameter of the female screw part.

The object of the present invention is to prevent the encroaching and the seizure between the bolt and the female screw caused by an oblique screwing of the bolt into the female screw when the bolt and the female screw are fastened together. Another object of the present invention is to manufacture the bolt in a low cost, by using said bolt, the encroaching and the seizure between the bolt and the female screw caused by a oblique screwing of the bolt into the female screw are certainly prevented. Said objects may be attained by a bolt consisting of a column part and a polygonal pillar part extending from an end of said column part wherein a complete thread is formed on said column part and a screw blade continuing to said complete thread is formed on said polygonal pillar part.

L'invention concerne une vis à extrémité ogivale ainsi qu'un procédé pour l'obtention de cette vis.

Ce procédé comprend une étape de frappe pendant laquelle on réalise la tête et la tige de la vis puis une étape de roulage pendant laquelle on forme les filets caractérisé en ce qu'on réalise l'extrémité ogivale (2) de la vis (1) avant l'étape de roulage, la forme de l'enveloppe de l'extrémité ogivale correspondant sensiblement à celle obtenue après l'étape de roulage.