Rheocasting – SAG’s innovative casting process brings lightness to vehicle construction

Innovative technologies for processing light metal alloys have undergone enormous development in recent years. These include rheocasting – a special casting process in which liquid aluminium is cooled and stirred until it reaches semi solid.

SAG is the technology leader in rheocasting – a special casting process in which aluminium is casted in a semi-solid or semi-liquid state. This semi-solid process has many advantages.

SAG is the only manufacturer in the world to use rheocasting to manufacture components such as safety cab suspensions for trucks or air reservoirs for the automotive industry. The demand for these lightweight and particularly robust components is rising strongly and production capacities at SAG’s Lend site have recently been greatly expanded thanks to strong demand from the passenger car industry. A total of more than EUR 3.6 million has been invested in the expansion of the rheocasting facilities in recent months.

At the SAG plant in Sweden, more than 250,000 rheocasting components are produced annually in 3-shift operation for large truck manufacturers such as VOLVO and Scania.

The rheocasting process in Lend/Salzburg produces special components for the automotive industry.

120 kg weight saving with only three rheocasting parts


According to EU climate targets, greenhouse gas emissions from new passenger cars are to be reduced by 37.5% by 2030. A target of 31% by 2030 is to apply to new light commercial vehicles. The automotive industry must therefore step up its efforts in climate protection and massively reduce the average fuel consumption of all vehicles.


Rheocasting makes a significant contribution to CO2 reduction in the automotive sector. With the particularly light and durable aluminum components, up to 60 % weight reduction can be achieved in automobile construction (compared to steel parts). Less weight means lower CO2 emissions. And therefore easier to achieve climate targets. But rheocasting can do even more.

The advantages of rheocasting at a glance


  • Parts can be manufactured in all shapes with precise final dimensional adaptation
  • Elimination of mechanical post-processing, thus extremely cost-efficient production
  • Weight reduction of up to 60 % for the same load capacity and service life of the elements compared to steel components
  • This significantly reduces fuel consumption and CO2 emissions.
  • Very good weldability


For example, the net weight of trucks can be reduced by 120 kg by using only three SAG rheocasting components. This in turn significantly reduces fuel consumption and CO2 emissions.

The advantages of rheocasting are versatile and the SAG development team works continuously together with the customers on the development and advancement of the application areas of rheocasting.



Less weight = less CO2 emissions

The advantages of rheocasting are versatile: The parts can be manufactured in all shapes – specifically adapted to the respective installation space. This is extremely cost-efficient due to the elimination of mechanical post-processing. In addition, the parts are extremely robust and have a low weight. Another important feature that distinguishes rheocasting from standard die casting is that the components are very easy to weld.

The achievable weight reduction of up to 60 % compared to steel components is particularly interesting for vehicle construction – and this with the same load capacity and service life of the elements. Thus, the net weight of vehicles, which tends to increase due to the design, can be massively reduced by using weight-optimizing SAG rheocasting components.

This reduces fuel consumption and thus CO2 emissions (with a weight saving of 120 kg, approx. 0.3 tons less CO2 per year and truck*).

Rheocasting offers a complete package of advantages for which VOLVO awarded an innovation prize to SAG in 2018.


Learn more about Rheocasting

Learn more about the rheocasting process with the Whitepaper “Semi-Solid Casting of Aluminium from an Industrial Point of View” from Johannes Winklhofer, head of the rheocasting division at SAG.

Learn more about Rheocasting