The BT-Spannschloss® (turnbuckle) is part of an easy to use connection system – without additional materials and tools.

The BT-Spannschloss® (turnbuckle) enables efficient and precise assembly and durable connections for precast concrete elements. By using BT-Spannschloss® (turnbuckle) and corresponding connection materials, precast elements can be joined together without using mineral grouting. This means no curing or standstill times due to low temperatures. The BT-Spannschloss® (turnbuckle) can be fully loaded
straight away. You can view the application of BT-Spannschloss® in our product video.


  • dry screw connection  
  • no joint grouting, no special tools
  • can be loaded immediately, no curing times
  • assembly regardless of weather, even in low temperatures or precipitation
  • able to be disassembled – removal of temporarily installed structures
  • three-point connection possible


The building inspection approval (Z-14.4-599) certifies the reliability of the product. The BT-Spannschloss® (turnbuckle) is offered in three sizes – M12, M16 and M20 – and is available in galvanised or
stainless steel.


  • Angle support walls in flood protection
  • Residential and commercial construction
  • Agricultural systems (e.g. bio-gas systems, silos)
  • Sewer and civil engineering (e.g. shaft structures, media channels, amphibian tunnels)
  • Temporary structures


For each of the three sizes of the BT-Spannschloss® (turnbuckle) there is a suitable recess body. The standard version of the recess body is made of polyethylene and has sloping sides to ease the removal after production. It is possible to customize the recess body in dimension or shape according to customer requirements.

The PE recess bodies are particularly dimensionally stable and can therefore be reused many times. They enable a particularly stable positioning of the anchors and also ensure sufficient concrete covering for the anchor and the BT-Spannschloss®. They can be equipped with magnets for faster and more reliable application. Depending on the installation situation, however, it is also possible to screw or drill into the recess bodies if required.