Description and Translation of DIN 7504 Fasteners
DIN 7504 fasteners, a specialized German standard for automotive and industrial hardware, function as hexagon weld nuts designed for permanent installation in sheet metal and structural components. Their primary role is to create robust threaded connections in welded assemblies, providing reliable clamping points for bolts in automotive bodies, machinery frames, and metal structures. These nuts facilitate efficient assembly by eliminating the need for pre-drilled threads, ensuring strong load transmission in welded joints.
In terms of materials, DIN 7504 fasteners are predominantly manufactured from low-carbon steel (e.g., DC04 and St37-2 per DIN standards) optimized for welding compatibility. This material ensures good weldability, minimal spatter formation, and sufficient mechanical strength after welding. For corrosion-resistant applications, zinc-coated low-carbon steel variants are specified to enhance durability in humid or mild chemical environments.
Surface treatments include zinc plating with chromate passivation for improved corrosion resistance, phosphate coating to facilitate welding processes, and thin organic coatings for temporary rust protection during storage and transportation. These treatments optimize weldability while extending service life in operational environments.
Key characteristics of DIN 7504 fasteners include standardized metric threads, hexagonal profiles with weld projections, and precise dimensional tolerances ensuring welding accuracy. Their mechanical attributes feature appropriate tensile strength (minimum 300 MPa) post-welding, good ductility to absorb welding stresses, and uniform thread geometry. Additionally, they exhibit consistent weld strength and reliable thread performance, making them indispensable in automotive manufacturing and metal structure assembly.
| Thread Size | ST2.9 | ST3.5 | ST4.2 | ST4.8 | ST5.5 | ST6.3 | ||
| P | Pitch | 1.1 | 1.3 | 1.4 | 1.6 | 1.8 | 1.8 | |
| a | max | 1.1 | 1.3 | 1.4 | 1.6 | 1.8 | 1.8 | |
| dk | max | 5.6 | 7 | 8 | 9.5 | 11 | 12 | |
| min | 5.3 | 6.64 | 7.64 | 9.14 | 10.57 | 11.57 | ||
| k | max | 2.4 | 2.6 | 3.1 | 3.7 | 4 | 4.6 | |
| min | 2.15 | 2.35 | 2.8 | 3.4 | 3.7 | 4.3 | ||
| r | min | 0.1 | 0.1 | 0.2 | 0.2 | 0.25 | 0.25 | |
| R | ≈ | 5 | 6 | 6.5 | 8 | 9 | 10 | |
| dp | 2.3 | 2.8 | 3.6 | 4.1 | 4.8 | 5.8 | ||
| Drilling range(thickness) | 0.7~1.9 | 0.7~2.25 | 1.75~3 | 1.75~4.4 | 1.75~5.25 | 2~6 | ||
| Socket No. | 1 | 2 | 2 | 2 | 3 | 3 | ||
| M1 | 3 | 3.9 | 4.4 | 4.9 | 6.4 | 6.9 | ||
| M2 | 3 | 4 | 4.4 | 4.8 | 6.2 | 6.8 | ||
| Lg (min.) | - | |||||||
| ①,Material: Be made of either of case hardening steel as specified in DIN 172100 or steel for quenching and tempering as specified in DIN EN 10083-1 and DIN EN 10083-2 (at the supplier's discretion), use of steel grades of equivalent quality being permitted | ||||||||
Self-drilling screws sourced for specified sheet, section and installation conditions with the required head, point and coating.
Roofing, cladding, light-gauge steel and equipment assembly where drilling capacity is validated for the substrate.
Suitability must be approved against the customer drawing, joint design and service conditions. Product-specific numbers are not published until confirmed by Shuojia and the selected manufacturing partner.
Drawing- and sample-based requests are reviewed with qualified manufacturing partners. State any required material certificate, dimensional report, thread-gauge result, hardness record, coating-thickness report or third-party inspection before quotation.
State the complete standard designation and revision for the Self-drilling Screw, or attach a controlled drawing. Similar product names do not guarantee dimensional interchangeability.
Specify the required material, property class or grade for the Self-drilling Screw. The proposed supply is confirmed against those requirements before quotation.
Confirm diameter, length, head, drive, drill point, washer, substrate thickness, coating and test requirement. Add any tolerances or mating-part details that control fit or function.
State the service environment, coating system, colour, thickness and corrosion-test requirement. Shuojia will confirm the available Self-drilling Screw sourcing route against the RFQ.
Request the exact records needed, such as material certificates, dimensional results, thread-gauge checks, hardness results or coating-thickness reports. Availability is confirmed in the quotation.
They depend on the final Self-drilling Screw specification, quantity, tooling, finish, inspection and packing. The written quotation confirms all three before an order is placed.
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