Connection quality and corrosion resistance with Tobsteel

Adverse conditions take their toll and fasteners have to withstand all kinds of extremes to perform. TOBSTEEL explains how its large inventory of special materials cover every corrosion resistance class...

The standards committee of the International Standard Organisation (ISO) is meeting the continuously evolving requirements of stainless steel fasteners. ISO has again set the requirements for more responsibility, safety and material awareness in the industry and in the construction sector with the latest edition of ISO 3506‐1:2020 (screws), of ISO 3506‐2:2020 (nuts) and the new ISO 3506‐6:2020 (guideline for selection and characteristics of stainless steels and nickel alloys for fasteners).

Due to this actualisation of standards of ISO 3506, the materials of CRC IV and CRC V in TOBSTEEL stock are now also classified into the new steel grades. A simplified classification of the most common materials of the TOBSTEEL product range can be found at tinyurl.com/tobsteel.

 

There are hundreds of different screws, but they are not all of the same quality

 

Adverse conditions take their toll. A challenging climate, the huge forces experienced in buildings and special hygiene requirements – products have to withstand all these extremes and the selected material and quality must be just right. It’s a huge responsibility. Those responsible for the material selection of a project for their company or a customer will know the five different corrosion resistance classes (CRC) and also how to calculate the corrosion resistance factor (CRF).

Professionals can use TOBSTEEL’s TOBspecials document for assistance and reference tinyurl.com/tobspecials. From page 60 you can find a short overview concerning the material selection (taking into consideration DIN EN 1993‐1‐4:2015‐10/Eurocode 3 – annex A) and the determination of the required corrosion resistance class.

Just calculate a few examples by yourself. You will clearly see why to use only fasteners of CRC V (A8 = HCR) for tunnels and swimming halls or why the need for sea water‐resistant fasteners of CRC IV (D6 = DUPLEX) is continuously growing.

Do you know of our new SUPERDUPLEX D8 of CRC V, which is used mainly in sea engineering, e.g. for big desalination plants? On the basis of your calculation result you will understand why in Europe screws and fasteners of CRC III (A4 materials) are currently the standard solution for cities with a lot of traffic.

We are used to extreme conditions and face the toughest challenges on a daily basis. TOBSTEEL offers an extremely high inventory of special materials for every corrosion resistance class. Highest quality and sustainability – this is our contribution to continually improve important connections in this world.