Car Body Megacasting Components: And the Repair?

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Manufacturing components using megacasting saves money in production. But what happens when the components need to be repaired?

Elon Musk did not invent the electric car—but he was the first to put it into mass production. Nor did he invent the production of ever larger and more integrated components using die casting—this trend is older than the Tesla brand. But he took it to new extremes in the production of the Models 3 and Y, for which he had complete front and rear cars produced "from a single cast" in huge die-casting machines. Perhaps even more importantly, he gave this process a name that was typical of him and sounded as spectacular as possible: Gigacasting.

This has now become established in the industry, although experts such as Sebastian Lüttig, Partner and Director Mobility and Transportation at the management consultancy Schlegel & Partner, prefer to speak of megacasting. "Gigacasting comes mainly from Tesla-speak," explained Lüttig in his presentation at the Würzburg Bodywork and Damage Days on March 20, 2026.

A New Dimension in Aluminum Die Casting

In principle, the process is no different to conventional aluminum die casting—just in a new dimension. According to Sebastian Lüttig, we talk about megacasting when the clamping force of the mold exceeds 6,600 US tons. The greater the clamping force, the larger the parts that can be cast—it's as simple as that.

The largest systems now installed in the automotive industry have even reached 11,000 US tons of clamping force, and larger ones are already being planned. This means that individual parts with a surface area of several square feet can be produced.

One Cast Part Replaces up to 100 Sheet Metal Parts

The appeal of this production method for car manufacturers lies in the integration of parts. Depending on the complexity of the comparative design, a large cast part replaces 70 to 100 components. This not only saves an enormous amount of working time, but also weight, as many material overlaps and joining elements are eliminated. As a result, costs are reduced by 15 to 30 percent compared to a conventionally manufactured assembly, according to Sebastian Lüttig—Tesla is even talking about 40 percent.

And it is indeed to Tesla's credit that its vehicles are significantly lighter than comparable competitor models. The vehicle price is also lower than that of other "Made in Germany" models, although the proportion of body production cannot be precisely quantified.

Advantages of the Process

No wonder that more and more OEMs are now relying on this production technology. Most strongly in China, of course, where several favorable factors come together:

• A new vehicle platform has to be designed for the use of large castings—something that Chinese manufacturers are currently doing anyway.
• Large quantities are necessary to amortize the high investment costs—Sebastian Lüttig speaks of 300,000 to 500,000 units over the lifetime of the vehicle model.

More Car Manufacturers Use Megacasting

But there are also an increasing number of users in Europe: Volvo, for example, has invested heavily in large casting technology. The traditional Torslanda plant was converted for the start of production of the battery-electric SUV model EX60 and supplemented with two casting systems from the Swiss manufacturer Bühler with a clamping force of 9,300 US tons. These will be used to produce the entire rear end of the EX60 in one piece.

According to Sebastian Lüttig, Volkswagen, Mercedes-Benz and Ford are also driving the process forward, while Nissan and Toyota are building up capacities for this technology in Japan. BMW, on the other hand, continues to rely more on classic steel body construction, such as the current Audi A6. Overall, the expert predicts annual growth of 33 percent in the production of large cast parts.

And How Can this Be Repaired?

But don't these large parts also lead to major problems during body repairs? The repair of accident damage to the body structure has so far been based on the method of cutting out damaged parts and replacing them. But if you have to replace "half the car", won't you reach the limits of cost-effectiveness much more quickly? In other words, are cars with large cast parts ultimately disposable cars that have to be scrapped after every major collision?

This question was addressed by several experts at the "Würzburg Bodywork and Damage Days", an event organized by our colleagues from kfz-betrieb. These included Helge Kiebach, Managing Director of the Institute of Automotive Technology. In his remarks, he referred in particular to the Tesla Model Y—by far the most widely used car to date with one or two large cast parts in the body structure; Tesla also produced the front end of the car using this technology for a certain period of time. However, this part was later replaced by a conventional structure. The reasons for this are unclear.

Well-Protected Cast Component

"The component in the rear of the Model Y is well protected," reported Helge Kiebach. In other words, it sits deep under the outer skin. "We have hardly found any cases where it has been damaged." It is also possible to repair sections, as Tesla has specifications for this—for example for welding cracks. Damaged sections of the large cast part can also be replaced with repair panels that can be glued and riveted in place.

"It is important," emphasized Kiebach, "to follow the individual guidelines for each vehicle." At Tesla, there are differences in body construction depending on the model year and manufacturing plant, even if the vehicles look the same on the outside. The car manufacturer estimates that it takes 46 hours to completely replace the cast part in the rear. The replacement part costs around $2,000.

Bernd Grüninger, Head of Expert Reports at Dekra, added the experts' empirical values. For example, only in five percent of accidents involving a car of this type are the large cast parts affected at all. And only in 1.5 percent of cases would the cost of the claim actually increase—the latter being a finding of the insurer Allianz.

This means that in many cases, accidents that cause such severe structural damage are not repaired anyway—the vehicle is a total loss.

Some Manufacturers Refuse Repairs

When it comes to ease of repair, it is not possible to draw conclusions about the market as a whole from Tesla or other established manufacturers. Helge Kiebach and Bernd Grüninger referred to vehicle concepts from Asia in which the large cast parts extend directly behind the outer skin or are positioned very close to the wheel.

This can quickly lead to damage to these components, even in the event of moderate accident severity. There are also manufacturers who completely refuse to repair these parts.

Experience With Chinese Manufacturers

In a panel discussion, K&L entrepreneur Peter Vogel shared his experiences of everyday workshop life with Chinese manufacturers: "Some people haven't even thought about how the car should be repaired. Then they say: 'You're the workshop, you must know that'."

Bernd Grüninger from Dekra also points out the difficulties of producing a reliable expert opinion for such vehicles. In any case, experts face additional challenges with large castings. In the event of major damage, a vehicle measurement is mandatory in order to determine whether the large cast part could be damaged. Extensive disassembly work is also necessary for a visual inspection. Crack detection equipment would then also have to be part of the expert's equipment, said Grüninger. Insurers must also learn to accept the additional work involved in assessing damage, added Michael Zierau, Head of Technology at the Central Association of Bodywork and Vehicle Technology.

Ultimately, it is the same as with all other new technologies: reputable and experienced car manufacturers take care of the repairability of their vehicles, and with new and unknown suppliers it becomes difficult—whether with large castings or not.

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