By Dr.-Ing. Christoph Blunk

What is DIBt and Why It's Relevant?

In structural engineering and construction, product quality and performance are non-negotiable. Independent validation by an accredited third-party body is essential to ensure compliance with design specifications, industry standards, and long-term structural integrity.

That’s where DIBt comes in. The Deutsches Institut für Bautechnik (DIBt) is Germany’s federal authority responsible for technical approvals of construction products that don't fall under harmonised European standards (hEN). Its approval process ensures that products used in structural applications meet the highest standards of safety, performance, and long-term reliability.

DIBt certification isn’t just a German requirement, it’s recognised globally as a benchmark of quality and technical credibility. Therefore, when you see that a product has DIBt approval, you know it has been rigorously tested and independently verified for use in safety-critical applications. That level of trust is why so many specifiers, engineers, and contractors actively seek DIBt approved products when selecting fastening systems.

 

How Lock Bolts and Blind Fasteners Work

Lock bolts and blind fasteners are critical in structural and industrial applications where strength, precision, and (due to assembly complexities and installation location, for example) come into play. Lock bolts are high-strength, vibration-resistant fasteners typically used in steel frameworks, rail infrastructure, and heavy machinery. Unlike traditional bolts, lock bolts create a permanent connection by swaging a collar onto the pin, ensuring a tight, secure fit that won't loosen over time.

Blind fasteners, on the other hand, are designed for applications where access is available from only one side of the joint - hence "blind". They offer a practical solution for tight spaces or enclosed structures, such as those in transportation, shipbuilding, and aerospace.

What these fastening systems have in common is the need for absolute reliability, which is realised by creating a mechanically maintenance-free connection through the unique installation process. They’re often used in places where failure isn’t just inconvenient - it’s potentially catastrophic. That’s why certification and traceability matter.

 

What It Takes to Get DIBt-Approval

Achieving DIBt approval requires thorough engineering validation, with products meeting or even exceeding stringent safety standards. That’s why DIBt approval carries so much weight in the industry. The process is highly detailed and technically demanding. Products must undergo independent laboratory testing under strict conditions, often including:

  • Tensile and shear testing
  • Fatigue resistance
  • Corrosion performance

Beyond mechanical testing, as manufacturers, we must provide complete documentation on product design, material composition, production processes, and quality control systems. DIBt approval is only maintained when a product can demonstrate consistent performance over time and under real-world conditions.

This scrutiny ensures only products meeting these standards are approved for certified structural use - a guarantee backed by legally recognised technical validation.

 

Why DIBt Certification Matters in the Real World

For contractors, engineers, and project managers, using DIBt approved fasteners isn't about ticking a box, it’s about reducing risk and improving outcomes.

Many public infrastructure and industrial projects in Europe require DIBt approved components as part of compliance with building regulations. Even when not legally required, using DIBt approved products ensures quality, reliability, and traceability.

In addition to this, when specifying projects, the use of DIBt approved products helps prevent the downstream costs of failure, such as regular maintenance and repairs, legal claims, delays, or even safety incidents. In critical structures like bridges, cranes, or transport systems, a failed fastener can have serious consequences. DIBt certification provides assurance that the product has been tested for precisely those conditions.

 

How to Identify a DIBt Approved Fastener

If you're specifying or sourcing fastening products, it pays to know what to look for. Products carrying DIBt approval are typically accompanied by:

  • An official DIBt approval number. These are in the format of Z-XX.X-XXX
  • Z = Zulassung (approval)
  • 4 = The relevant approval category
    • 14 = Metal Construction and Construction Techniques
      • 4 = Fasteners and Connections for Metal Structures
    • 591 = Unique Identifier
  • A Ü-mark (Übereinstimmungszeichen) – German national conformity mark, in accordance with the general building authority approval (abZ)
  • Manufacturer documentation, such as technical datasheets or declarations of performance (DoPs)

If you’re unsure, we recommend that you ask your supplier for verification documents and confirm that the product you're using matches the specific approved configuration (including material, dimensions, and installation method). Many manufacturers also publish approval certificates and technical assessments on their websites, or via public registers like DIBt’s approval database.

 

DIBt Approval is More Than a Label

In structural fastening, shortcuts can be costly, and potentially life threatening. DIBt approval represents more than a logo on a datasheet. It’s a technical endorsement that a product performs exactly as required, under the conditions it was designed for.

When it comes to lock bolts and blind fasteners, using products with DIBt approval is a strong strategic decision. It gives a guarantee of engineering integrity, which in a world of increasing complexity, is more valuable than ever.

If you’re evaluating fastening options for your project, to help you make the right choice, we’re happy to provide technical advice backed by real-world experience. Get in touch to request a conversation with one of our engineers.