A Bond for Life or Just for Now? How EVs Are Reshaping Automotive-Die-Casting Partnerships

In the early twentieth century, it was impossible to foresee the direction in which this relationship would evolve. For a long time, die casting served as a necessary intermediate step in the production of printing type made from low-melting tin-lead alloys. Industries outside printing had little use for the process. Soon enough, however, the then still young and rapidly expanding car industry discovered its taste for fast, affordable mass production. The die casting industry was a dream partner, though initially only for small parts made from zinc, lead and tin alloys.

In 1927, the Czech engineer Josef Polák developed the pivotal technology that would pave the way for the two industries' shared good fortune: the cold-chamber die casting machine with vertical injection. Only this invention created the technical conditions needed to use higher-melting alloys such as aluminium or magnesium in industrial die casting. While the automotive industry was impressed, it remained sceptical for the time being. It had many processes to choose from and tended to favour the most pragmatic solutions available. And so the die casting industry won the carmakers' trust only gradually.

The two oil shocks of the 1970s prompted the automotive industry to rethink its approach. It began looking for ways to reduce the weight of vehicles to make them more economical. The die casting industry saw its opportunity and pulled out all the stops to make even more die-cast car parts feasible and win the attention of the car industry. Investment grew in better aluminium alloys and in larger machines with higher clamping forces.

The automotive industry was delighted. Die casting was simply too unique to ignore. Over time, more and more carmakers began using aluminium-alloy die castings even for mechanically highly stressed parts. The two industries tied the knot for life and it seemed that nothing and no one could stand in their way.

A new hunger for structural parts

Then, in the 2010s, another upheaval occurred. Driven in particular by advances in battery technology, stricter emissions regulations and foreign competitors, the European automotive industry found itself compelled to strike out on a new path: electromobility.  

For the die casting industry, this was both good news and bad. The good news was that car manufacturers had no intention of abandoning die-cast lightweight parts; in fact, they were developing an even greater appetite for them.  The bad news was that they could only partially bring their partners, along with their many small and medium-sized suppliers, with them on this new path. The consequences were soon to be felt.

A first major step on the automotive industry's new path came from Tesla in 2020. The American carmaker installed a machine for so-called Gigacasting on its production floor. This enabled the company to produce large aluminium structural components in a single shot, using presses with clamping forces ranging from 6,000 to over 9,000 tonnes. This significantly reduced assembly time, as far fewer individual parts had to be joined together, rendering expensive welding robots partly redundant.

However, the die casting industry was somewhat unsettled by its soulmate's new obsession. For most foundries, implementing Gigacasting in-house was — and still is — difficult, mainly because of the high investment costs involved. On top of that, it is logistically easier to produce the unwieldy Gigacasting components directly next to the OEM's final assembly line. Transporting them by lorry would be uneconomical and risky. As a result, a substantial portion of die cast production has migrated into the OEMs' own plants. 

According to a recent study by Johannes Messer Consulting (JMC), conventional cars with combustion engines contain between 50 and 100 aluminium cast parts, whereas BEVs contain only 10 to 40. This is particularly problematic for small and medium-sized foundries that had specialised exclusively in components for conventional powertrains. The shared past cannot simply be carried over into the new electric future. The pressure to adapt is considerable.

The production of new parts often requires new technologies, such as vacuum and semi-solid die casting, as well as high leak-tightness requirements. This level of investment is beyond the capacity of many small and mid-sized plants. The situation is further complicated for the foundry industry by the investment backlog that has built up over recent years, making the switch to new parts for electric cars more difficult.

A relationship out of balance

The die casting industry is feeling uneasy. It is by no means yet clear how quickly the further transformation will unfold, or just how sweeping the changes for foundries will turn out to be. But the car manufacturers are feeling the pressure too. Just a few years ago, Audi announced that it would stop developing new combustion engines from 2026 in order to go fully electric by 2032. However, owing to unexpectedly faltering demand, the company — like other manufacturers — has since put that plan on hold. Gigacasting, too, may end up playing a smaller role than initially thought, given the high investment costs, the potentially adverse effects on insurance premiums, and the limited scope for repair.

According to the study by Johannes Messer Consulting (JMC) mentioned above, the share of supplies destined for automotive products in Europe now accounts for more than 70 per cent of die casting foundries' total output. Overall, it is clear that while the automotive industry needs die casting, it is not as dependent on the relationship as its partner is. An unsettled automotive industry leaves a die casting industry facing an existential threat — but not the other way around. And so the automotive industry feels its way forward along its chosen path, followed by a visibly battered die casting industry.