Screws remain one of the most important connectors in modern timber construction. No matter whether storeys are added to existing buildings, or single-family houses or multi-storey residential buildings are built – these tried and tested connectors are used in all kinds of projects in different places and in large quantities. For Sihga’s technicians, this is a good reason for continuously improving the company’s range of wood construction screws and thus optimising it for its customers.
Optimised screw head
The partially-threaded screw Gofix MS II has been a tried and tested connector on countless construction sites. “MS” stands for “multi-stage head” and describes the stepped profile of the screw head developed by Sihga. According to timber construction expert and Sihga technician Johann Gruber, the main advantage of this system is the effortless fastening of the screw even with a diagonal angle while reducing the splitting effect in the wood at the same time. Thanks to the broad upper part of the head, the pull-through resistance remains high enough, however, to be able to bear heavy loads.
Depending to the customers’ needs, the Upper Austrian company offers dimensions of 4 x 30 up to 10 x 600 mm. “Thanks to our Gofix series, we are able to fully supply our customers with only a few optimised types of screws. This makes work on the construction site considerably easier and has a positive effect on our customers’ warehousing as well”, tells us managing director Jane-Beryl Simmer.
Suitable for end grain wood as well
Sihga developed the Gofix X+ for the bearing of heavy loads. The screw can be driven into the wood at any desired angle to the grain © Sihga
The fully-threaded screw Gofix X+ for fastening blunt wood connections, such as CLT walls or joists, is also part of Sihga’s product range. This screw is admissible for all screw-in angles from 0 to 90° to the fibre. When fastening it, a specially developed screw tip allows for an even more precise positioning of the screw and a mostly tension-free fastening. Furthermore, the “Sihga Tip” facilitates small edge and axial distances.
Another characteristic of the Gofix X+ is the special screw head with a deep, recessed drive, which makes the work of timber construction workers easier by basically preventing camming out when fastening the screw. Also, an optimised thread makes the fastening easier thanks to its low insertion torque.
For the fixing of wood ceilings on steel beams, of steel angle brackets on wood beams or for similar wood-steel-connections, Sihga developed the Gofix S+. Similarly to the Gofix X+, the S+ model also has an optimised tip, a deep recessed drive and the adapted thread for an optimal transmission of forces.
For two years already, all of the three types of screws described have obtained positive expert opinions with regard to seismic loads and the fastening with impact drilling machines. “Thanks to this expert opinion by the University of Innsbruck, our customers can profit from the advantages of this fast and effortless working method without having doubts”, says Simmer.
Lifting 22,000 times without residues
The load attachment device Pick was developed by Sihga so as to guarantee the fast and safe lifting of elements © Sihga
Everyone who has worked on a construction site before knows that suspended loads always involve a certain risk. Also, speed plays a central role in the construction of buildings. With that in mind, Sihga developed the load attachment device Pick for the lifting of CLT, glulam, frame and solid wood elements.
The self-tensing construction requires only one blind hole with a diameter of 50 mm and a depth of 70 mm. This blind hole is drilled either with the aid of the gauge supplied with the Pick or directly during production using a machining centre.
After drilling, the Pick is inserted in the hole. As soon as the shackle on top is pulled by the crane chain, the Pick is anchored in the wood. Independently of the angle in which the chain is attached to the shackle, the thread inside the Pick is always tensed, and not subjected to other types of forces, which means that even the safe raising up of wall elements, which are lying on the floor, does not pose a problem.
High installation tolerance
Sihga’s wall connector Hobafix HFM has a particularly high installation tolerance © Sihga
After the walls are lifted from the lorry with the Pick, the elements should be placed rather quickly. For this purpose, Sihga developed the Hobafix HFM, a connector for walls with a particularly high installation tolerance of 14 mm. The elastic pre-tensed installation connector for mounting is fastened by using a 30 mm-wide and 17 mm-deep groove and can be seen at any time during the installation.
By guiding into the installation groove an immediate angularity of the wall elements is achieved. The system can be used for walls of any desired thickness. According to Simmer, about 80% of working time can be saved thanks to the rational placing of the Hobafix HFM. This is just another example of how Sihga succeeded in making its customers’ everyday work safer and more efficient.
