A smart new way to connect wood and concrete 24 June 2024

Carpenters and wood construction specialists benefit from reliable anchorages that are easy to install when fastening wood components to concrete. fischer’s UltraCut FBS II concrete screws fulfil particularly high requirements, as their variants and accessories cover multiple applications in roof and timber construction.

fischer offers 29 versions of the Ultracut FBS II in zinc-plated carbon steel as well as stainless steel with long usable lengths and European Technical Assessments (ETA) for these applications. Depending on the variant, the screw lengths for wood construction reach up to 190mm at a diameter of 8mm, up to 280mm at a diameter of 10mm, up to 210mm at a diameter of 12mm and up to 240mm at a diameter of 14mm. This offers the advantage of maximum flexibility and a versatile range of applications. 

Wood construction specialists and carpenters can adjust beams and joists even more easily with the new FSW adjusting washer combined with the Ultracut FBS II hexagon head – a clever solution for evenly aligning purlins spirit levels on what tends to be uneven surfaces while erecting roof trusses and prefabricated houses. The adjusting washer FSW can be fastened to concrete in no time together with the zinc-plated Ultracut FBS II.

The concrete screw is simply inserted into the drill hole using the push-through method of installation – no further drill hole cleaning is required during vertical drilling in floors and ceilings or when using hollow drills with vacuum functions. Up to three different approved screw-in depths can be used to match the existing load for each FBS II variant.

The concrete screw’s patented thread geometry and large core diameter support high shear and tensile loads in concrete, which allows many applications to be carried out with fewer fastening points. The FBS II’s flanks cut deep into the concrete as it is inserted. This optimum fit ensures reliable force transfer, anchorages free of expansion pressure as well as low edge and axial spacing for simple and safe installation. The FBS II can be unscrewed, lined and readjusted up to two times without being damaged in compliance with regulations. The ribs under the head prevent the concrete screw from unintentionally loosening. 

Further advantages include the fact that the FBS II can be reused under certain circumstances, for instance to temporarily anchor inclined formwork supports in fresh concrete that hasn’t fully set yet, as well as fresh concrete with a strength of just 10 N/mm². The measuring sleeve should be used to test the wear of the thread and ensure it still works sufficiently. Its ETA for applications in concrete covers fire resistance class R120 and, in most cases, seismic applications in performance categories C1 and C2. 

fischer’s concrete screws cover a wide range of applications with various diameters of 6mm to 14mm in its zinc-plated versions and 8mm to 12mm in stainless steel (R) variants and many different head types. They can be used for indoor and outdoor applications, multiple fastenings and much more.


Becca England Assistant Editor t: +44 (0) 1727 615 413

Becca is the latest member to join our team and is eager to get stuck into the world of fasteners. She brings an enthusiastic and fresh outlook on what we do editorially and will be leading our social media activity – including sourcing material, editing articles and posting online.