Self Clinching Technology
Clinch Fasteners Are Pressed Into a Component With High Axial Force
Self-clinching is a joining process used to attach fasteners, such as clinch nuts, clinch studs, or standoffs, to ductile sheet metal. Self-clinching technology is especially valued for its simplicity, cost-effectiveness and suitability for thin sheets and dissimilar materials.
It eliminates the need for adhesives, welding, or secondary threading processes. The result is a reliable, high-strength joint suitable for a wide range of industrial applications.
How Does Self-Clinching Work?
A self-clinching fastener is placed in a pilot hole in the sheet metal. A press installation tool is used to apply high axial pressure and force the fastener into the sheet metal.
The pressing process causes the surrounding material to flow into a specially designed undercut and indentations on the fastener, such as knurls or ribs, securing the fastener firmly and permanently in place.
The undercut provides a mechanical lock that prevents the fastener from being pushed out. The underhead serration prevents rotation and provides stability to the sheet metal joint.
Once installed, the fastener becomes an integral part of the sheet metal, capable of withstanding high torque and push-out forces. It provides secure mounting points or threads for attaching other components, even allowing easy disassembly or replacement of parts at a later date.
Advantages of Self-Clinching
- Ensures consistent alignment and positioning due to the precision of the assembly process.
- Ideal for applications where tight tolerances are required.
- Requires minimal surface preparation and no additional treatment of the pilot hole.
- Fast installation process makes it suitable for high-speed production lines.
- Does not produce weld spatter, eliminating the need for cleaning or rework.
- Provides excellent load-bearing capacity, even in thin sheets.
- Ensures strong, vibration-resistant joints due to the interlocking design.
- Can be installed without damaging corrosion-resistant coatings or finishes.
- Ideal for outdoor and even waterproof applications.
- Uses less energy than welding, resulting in lower operating costs and reduced environmental impact.
- Eliminates the need for complex equipment or consumables such as adhesives or solder.
- Can be used in industries with stringent environmental requirements, such as automotive, telecommunications, medical, and electronics.
- Allows for easy disassembly and replacement of components, unlike non-reversible solutions such as welding.
- Simplifies repairs and upgrades in assembled products.
Requirements for Self-Clinching
Workpiece Material Specifications
The material into which the fastener will be installed must be ductile enough to allow for displacement and fusion with the grooves of the fastener. Brittle or hard materials are unsuitable because they will not deform sufficiently. The thickness of the sheet metal should meet the minimum requirements of the fastener. Sheets that are too thin may not provide enough material to flow into the undercut of the fastener.
Pilot Hole Specifications
The size and shape of the pilot hole must meet the design requirements of the fastener to ensure proper seating and alignment. Precision is critical; mismatched, oversized or irregular holes can compromise fastener strength.
Installation Force
Installation requires applying a consistent and controlled force to properly embed a fastener. This force is typically applied with tools designed specifically for self-clinching, consisting of hydraulic or pneumatic presses. A force-controlled installation process provides consistent results.
Case Study
Automated Assembly of an Instrument Panel Carrier for an OEM Platform
For the production of an instrument panel carrier, we provide a fully integrated final assembly system designed for efficient and precise manufacturing.
The comprehensive assembly solution includes:
- Self-clinching fasteners such as clinch nuts, spacers, and specialty fasteners
- Transfer die modules for the automated in-die installation of clinch nuts and spacers
The fastening process is fully automated, allowing components to be assembled in the press in a single step. Advanced process monitoring and documentation ensures traceability and compliance with manufacturing standards. This system supports high-volume production with efficiency and consistent quality. It has been successfully implemented in six countries in North America, Europe, and Asia.
Self-Clinching vs. Self-Piercing Fasteners
There is a basic distinction between self-clinching and self-piercing fasteners. While self-clinching fasteners are pressed into a pre-drilled component, self-piercing fasteners do not require pilot holes. With the latter, a slug is formed during the setting process.
The choice between self-clinching and self-piercing fasteners depends on the material properties, application requirements, and manufacturing process. In general, self-piercing fasteners eliminate the need for pre-drilling, saving time and money in certain applications.
Request for Quotation
Would you like us to call you back? Leave your telephone number or e-mail, and we will get back to you as soon as possible!
