The Chinese automaker’s premium EV brand, Zeekr, takes advantage of the “gigapress” die casting technique for its Zeeker 009 MPV (lead photo). This means the entire rear underbody section is made of one piece, helping them eliminate almost 800 weld points. This helps them cut defects, make the vehicle lighter, boost its structural stiffness, and improve the overall ride.

Metal and plastic die casting has long been used in manufacturing, but its application to large aluminum underbodies in car manufacturing is relatively new.

The newest and biggest press made by equipment manufacturer, IDRA, has a clamping force of over 9,000 tons. It can punch out the front and rear underbodies which support the car’s outer skin and provide a platform for suspension components. The front and rear sections are then connected with large under-floor battery packs to form a three-piece EV chassis.

For Geely’s Zeekr brand, they use machines with a pressing power of 7,200 tons and can make the Zeekr 009’s underbody section which is around 1.4 meters long and 1.6 meters wide.

Other automakers turning to large die casting include General Motors for its Cadillac brand, and of course, Tesla.

Volvo Cars, which is majority owned by Geely, will also apply the technique, albeit in a smaller scale called “megacasting” for its next-generation EVs.

Meanwhile, Toyota is only starting to consider the use of megacasting for its manufacturing process. For the Japanese carmaker, they will prioritize flexibly enabling it to be used in vehicles of various shapes and sizes.

Using giga-casting though comes with risks, one of which surrounds the repairability of vehicles. With body sections cast into single pieces, that could make them harder to repair if damaged in an accident, even a low-speed fender-bender or rear-end crash.

With most cars that might call only for the replacement of a fender or a bumper. In the case of a gigacast vehicle, it could entail a significant repair, including a possible replacement of the car’s entire front or rear section.

To cope with the repairability issue, Zeekr will be able to change select parts of the larger die cast section in the event of a collision, rather than having to replace the whole thing.

Future Zeekr products (and in turn, likely Geely products) are expected to use the gigacasting method.