# US 10,871,181 B2 · Process for producing a connecting element as well as connecting element > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,871,181 B2 - Document ID: US10871181B2 - Status: Granted - Kind: B2 - Application number: 15/190,405 - Filed: 2016-06-23 - Published: 2016-12-29 - Granted: 2020-12-22 - Earliest claimed: 2015-06-23 - Assignees: Richard Bergner Verbindungstechnik GmbH & Co. KG - Applicants: Richard Bergner Verbindungstechnik GmbH & Co. KG - Inventors: Roland Bingeser; Helene Pramschuefer - Web page: https://patentgrep.com/patent/US10871181B2 ## CPC - F16B 33/06: Surface treatment of parts furnished with screw-thread, e.g. for preventing seizure {or fretting (corrosion preventing means F16B33/008; settable coatings for locking threaded members F16B39/225; deformable coatings for locking threaded members F16B39/34)} - B21H 3/02: external screw-threads {; Making dies for thread rolling} - C23C 10/28: using solids, e.g. powders, pastes - C23C 10/30: using a layer of powder or paste on the surface (using liquid suspensions of solids C23C10/18) - C23C 10/36: only one element being diffused - C23C 10/60: After-treatment - C23C 24/08: by application of heat or pressure and heat (C23C24/04 takes precedence) - C23C 28/3225: {with at least one zinc-based layer} - C23C 28/34: {including at least one inorganic non-metallic material layer, e.g. metal carbide, nitride, boride, silicide layer and their mixtures, enamels, phosphates and sulphates} - C23C 30/00: Coating with metallic material characterised only by the composition of the metallic material, i.e. not characterised by the coating process (C23C26/00, C23C28/00 take precedence) - F16C 11/02: Trunnions; Crank-pins (fastening crank-pins to webs, crank-pins integral with cranks F16C3/06, F16C3/22) - F16B: DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING (couplings for transmitting rotation F16D) - B21H: MAKING PARTICULAR METAL OBJECTS BY ROLLING, e.g. SCREWS, WHEELS, RINGS, BARRELS, BALLS (essentially from sheet metal B21D) - C23C: COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL (making metal-coated products by extrusion B21C23/22; covering with metal by connecting pre-existing layers to articles, see the relevant places, e.g. B21D39/00, B23K; metallising of glass C03C; metallising mortars, concrete, artificial stone, ceramics or natural stone C04B41/00; enamelling of, or applying a vitreous layer to, metals C23D; treating metal surfaces or coating of metals by electrolysis or electrophoresis C25D; single-crystal film growth C30B; by metallising textiles D06M11/83; decorating textiles by locally metallising D06Q1/04) - F16C: SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS ## Abstract In a method for producing a connecting element, in particular a bolt, a zinc anti-friction coating is applied to a blank made of a metallic base material. Subsequently, the coated blank is deformed in a deformation process to a desired final geometry of the bolt. The deformation process may, in particular, be a thread rolling process. The anti-friction coating is applied in particular by way of a zinc diffusion method. The bolt is in particular an engine bolt, specifically a connecting rod bolt. A bolt of this type has a durability as conventional bolts, but at the same time can be mounted repeatedly by virtue of the formation of the special anti-friction coating without the coefficients of friction increasing above permissible limits. ## Claims ### Claim 1 A method for producing a bolt, the method comprising: providing a blank of a metallic base material, the blank having a shank region and a head region; after providing the blank that has the shank region and the head region, applying a coating of zinc or zinc alloy on the blank as an anti-friction coating to form a coated blank; and after applying the anti-friction coating on the blank, forming a thread into the shank region. ### Claim 2 (depends on 1) The method according to claim 1, wherein the applying step comprises applying the anti-friction coating by a zinc diffusion method, and thereby bringing the metallic material into contact with the blank in powder form at an elevated temperature, and causing the metallic material to penetrate into the base material of said blank by virtue of a diffusion process. ### Claim 3 (depends on 1) The method according to claim 1, which comprises not subjecting the bolt to any further thermal treatment after forming the thread. ### Claim 4 (depends on 1) The method according to claim 1, which comprises applying an anti-friction lubricant to the anti-friction coating to set a defined coefficient of friction. ### Claim 5 (depends on 1) The method according to claim 1, which comprises applying the anti-friction coating with a layer thickness in a range of 5 μm to 30 μm before forming the thread. ### Claim 6 (depends on 1) The method according to claim 1, which comprises: providing a raw wire; forming a bolt-shaped pre blank; forming the blank by deforming the pre blank to form the head region and the shank region; subjecting the raw wire, the pre blank, or the blank to a thermal treatment for hardening; after the thermal treatment, applying the anti-friction coating such that the coating has a layer thickness in a range between 5 μm and 30 μm; and after applying the anti-friction coating, forming the thread into the shank region by a cold-forming method without performing any additional thermal treatment with temperatures greater than 220° C. after forming the thread. ### Claim 7 (depends on 6) The method according to claim 6, wherein the step of applying the anti-friction coating includes introducing the blank together with additional blanks and the zinc powder into a rotating drum. ### Claim 8 (depends on 7) The method according to claim 7, wherein the anti-friction coating allows for repeated tightening of the bolt up to deformation from at least five times and up to ten times. ### Claim 9 (depends on 2) The method according to claim 2, wherein the step of applying the anti-friction coating includes introducing the blank together with additional blanks and the zinc powder into a rotating drum.