Rear side member

Development & Production

The rear side member is an essential component for the Body in White (BIW) of the Audi A8 Space Frame structure. It is the connecting piece between the side rocker and the rear crush profiles. In close collaboration, Audi and GF contributed to the component’s development, especially the new high-strength casting alloy. GF Casting Solutions focused especially on the industrialization of the production process as well as the fulfillment of the high quality requirements for the serial part.

Challenges & Special Features

Overcoming the hurdles of serialization and achieving the high quality requirements have been challenges from technical perspective. Together as a strong team and with the customer, GF Casting Solutions excelled in fine-tuning the mechanical properties and dimensional quality. The mating surfaces on the rear side member towards the front of the car warrant optimal dimensional quality.

“Due to the exceptional freedom of design with cast components, this part – like many other structural castings – replaces an abundance of single components that would otherwise make up an assembly. Realizing all the functionality in just one part decreases not only the weight of the car body, but also significantly reduces the assembly time.”

Georg Zerling

Sales Engineer


  • complex structural part produced on a large die-casting machine with high requirements on the manufacturing process and product quality 
  • outstanding weight to energy absorption ratio


Customer Audi
Vehicle A8 (D5) 
Process Aluminum high-pressure die-casting
Material  AlSi10MnMgZnZr 
Weight 10.4 kg
Value Chain casting, punching, straightening, heat treatment, manual straightening, machining, assembly, conversion coating