A4 stainless steel renamed as R 21 December 2020

The benefits of fischer’s fixing solutions are visible in projects across the globe. For instance, its corrosion resistant steel anchors are required for multiple projects, including the development of the public transport network as part of the Le Grand Paris or in the Netherlands’ longest land tunnel. With this in mind fischer is now renaming its product range by changing A4 to R to clearly label stainless steel according to international standards.

The fischer Group of Companies is renaming its stainless steel products to comply with the CRC corrosion resistance classes (I to V) in accordance with DIN EN 1993-1-4. The fixings specialist is thereby aligning the terms for its steel anchors with the European standards for material selection for the design of steel structures. This ensures the product descriptions are harmonised and simplified on an international scale.

The move allows civil engineers and designers across the globe to see at a glance whether fixing solutions meet anti-corrosion requirements. The classification helps guarantee the building’s stability, preventing harm to life and limb. Suitable materials and measures depend on the environmental conditions. The level of corrosion exposure is much higher closer to seawater or in chlorinated swimming pools than in other areas, for instance.       

A tragic accident at an indoor swimming pool in Uster, Switzerland, demonstrated the importance of protecting individual construction elements including steel anchors from corrosion. During the accident in 1985, a 200 tonne concrete roof collapsed, burying 40 people beneath it and resulting in the loss of 12 lives. This was caused by the fixings being damaged by corrosion. CRC classifications can help prevent incidents such as these.

The letter R (which stands for resistant) signifies that stainless steel fischer products belong to corrosion resistance Class III (CRC III). Alongside austenitic steel, this will also include austenitic ferritic (duplex) steel. These products provide positive performance features and corrosion resistance due to advantageous alloying elements. They can be used for applications outdoors, in industrial and coastal atmospheres, as well as in damp locations in accordance with ETAs.

Steel fischer products made of the highest corrosion resistance Class V will bear the initial HCR (high corrosion resistance) in future. These stainless steels can also be used for particularly aggressive application conditions in addition to CRC III applications. These include alternating submersion in seawater or chlorinated atmospheres in indoor swimming pools.

The data in the fischer Fixperience design software will also undergo changes due to the renaming of the fixing specialist’s steel anchors. This will make it even easier for users to verify state of the art designs with corrosion resistant steel anchors that are valid across Europe. The altered descriptions and the classifications of the corresponding material numbers have also been applied to all approvals and evaluations.

fischer points out that products already on the market featuring the A4 designation can continue to be used. Structural engineering calculations and tenders that have already been created using the A4 description can still be carried out with products that have been renamed R. The product characteristics remain unaffected by the change of name.

A permanent, secure hold

Corrosion resistant steel anchors by the fischer Group of Companies are used in numerous projects across the globe. The corrosion resistant steel anchors are in high demand for infrastructure projects, such as the stainless steel FH II-I internal threaded anchor, which is being used to install power lines during the expansion of the public transport network in Paris.

The French capital is expanding with the Le Grand Paris project. The existing metro line 14 has been expanded by 6km and five new stations. Approximately 20,000 stainless steel internal threaded anchors – FH II-I – made by fischer were used to firmly and securely install the console systems of the power supply lines.  These have an ETA  for  cracked  concrete  as  well  as  a  visual  placement control. The chosen variant is suitable for threaded rods with a diameter of 10mm and a 15mm inner drill diameter. Numerous pull-out tests in various building segments demonstrated that this was the best solution for the application of the special bore in the prefabricated parts. The system combines high load-bearing capacity, reliability and assembly comfort along with cost-effectiveness. The FH II-I were fitted using the prior insertion method of installation with an anchoring depth of 70mm and a minimum fixture thickness of 150mm.

The installation experts also drilled 15mm holes into a plastic component in the concrete wall before positioning the fixings and expanding them quickly and easily against the drill hole wall using the internal threaded bolt. The console systems were each subsequently fixed to the concrete walls using stainless steel FIS A M10 x 110 threaded rods and two nuts also made by fischer.

Another example of a project that uses fischer’s stainless steel anchors is the Netherlands’ longest and second widest land tunnel, which is currently under construction. More than 1.7 million stainless steel fischer nail anchors – FNA II – were used to install fire protection plates to walls and ceilings as well as for other applications.

The project includes a new tunnel that will be 3km long and 73m wide upon its completion in late 2020. The fischer Group of Companies was able to successfully complete the installation of the fire protection plates to the walls and ceilings in close cooperation with the building contractor Kaefer Construction GmbH. The purpose of the post installed tunnel cladding is to protect the concrete construction in the underground traffic facility in the event of a fire.

The fire protection plates are installed in just a few installation steps. They are simply positioned on the wall or ceiling before being drilled through to create a drill hole into which the anchor is quickly placed with a pneumatic setting tool using the push-through method of installation. The FNA II expands automatically under load, during which the cone is pulled into the expansion clip and expands it against the drill hole. 

Claire Aldridge Deputy Editor t: +44 (0) 1727 743 889

Having spent a decade in the fastener industry experiencing every facet – from steel mills, fastener manufacturers, wholesalers, distributors, as well as machinery builders and plating + coating companies, Claire has developed an in-depth knowledge of all things fasteners.

Alongside visiting numerous companies, exhibitions and conferences around the world, Claire has also interviewed high profile figures – focusing on key topics impacting the sector and making sure readers stay up to date with the latest developments within the industry.