ROK-compliant bolt and nut testing for a safe infrastructure

In infrastructural structures such as bridges, viaducts, and locks, fasteners simply must not fail. Bolts and nuts must therefore comply with the strict quality criteria set out in the guidelines published by Rijkswaterstaat (ROK). The Metallurgical Laboratory of MME Group performs these ROK-compliant bolt and nut tests for suppliers of fasteners within civil engineering. In this way, you can be certain that your materials meet all safety requirements.

ROK: The standard for civil structures

The Richtlijnen Ontwerp Kunstwerken (ROK) describe the requirements and guidelines for the design of civil structures, including bridges, viaducts, locks, and tunnels.
It is extremely important that the materials used such as hot-dip galvanized preloaded bolts meet stringent quality criteria to ensure the safety and durability of these structures.

The ROK addresses, among other things, specific requirements relating to the strength and stability of civil structures. A key aspect of this is the test program for hot-dip galvanized fasteners. This program includes rigorous tests aimed at assessing the performance of preloaded bolts.

Test program

At a minimum, three proof load tests, tensile tests, hardness measurements, and microscopic examinations are carried out per batch to guarantee the quality and reliability of these components.

 

  • Proof load test: During this test, the bolt must not deform after being subjected to a specified load. This ensures that the bolt can maintain the correct preload in practice.
  • Tensile test: This test determines the force at which the bolt fails.
  • Hardness measurement (NS CTO 3L10314254): Also known in the Netherlands as the ‘spoorwegproef’. The hardness is measured just below the zinc coating. To prevent cracking due to hydrogen embrittlement, the hardness must not exceed 370 HV0.3.
  • Microscopic examination: Using a longitudinal cross-section in combination with hardness measurements, this test checks whether the bolt thread has not been carburized or decarburized.

MME Group: Your partner in quality and expertise

With years of experience and expertise, the Metallurgical Laboratory of MME Group has carried out many ROK tests for suppliers of renowned bolt and nut manufacturers. Our focus goes beyond quality control; our team is also ready to support you with failure analysis of broken fasteners.

In this way, MME Group contributes to the safety, reliability, and sustainability of infrastructural structures in the Netherlands. A Longer Life.

Contact

Would you like to learn more about our ROK-compliant bolt and nut testing, or do you have questions about our services? Please feel free to contact us. We are happy to assist you with all your questions and needs.

 

Together, we build a safe and sustainable infrastructure!

Contact us

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