The "industrial salt" screw is also moving to pure electric vehicles

The global wave of pure electric vehicle (EV) transformation is hitting auto parts manufacturers. It is believed that the internal combustion engine, represented by the engine, needs to use about 30,000 parts, while pure electric vehicles can be reduced by half. To turn the crisis into an opportunity, Japanese companies are doing everything they can to make the most of their technology.

"Due to the shift to pure electric vehicles, the screws have to change," said Masaji Lumber, president of Nicto Seiko, a major Japanese screw manufacturer. He held in his hand a screw that at first glance seemed unremarkable. Take a closer look with a magnifying glass, and there are grooves all over the screw teeth. This is one of the company's main products, the GIZA TITE.

After screws are screwed into the member, the object material deforms like clay and is embedded between the grooves. The cross section of the screw teeth is an asymmetric triangle, which is not easy to loose and fall off. This screw is suitable for the installation of small components such as sensors because it does not require nuts and can be firmly connected in small Spaces.

To improve the "power consumption" of pure electric vehicles, the weight of the car must be reduced, and parts need to use a lot of resins that are lighter than materials such as iron. GIZA TITE is not strongly fastened, so there is no need to worry about deforming the object material.

Nitto Seiko originally developed products for precision machinery such as game consoles and watches. "Cars have high safety requirements and must be redesigned into the best shape for each component that needs to be tightened," said Chiaki.

Screws are the "industrial salt" that all products need to use. Each car needs to use 2,000 to 3,000 screws. The design of pure electric vehicles is different from that of engine locomotives, and the function of screws also needs to be further improved. Lightweight is one of them.

"Screws play an important role in reducing the weight of pure electric vehicles," said Taji Furukawa, director of YAMASHINA, a major manufacturer of auto screws in Japan. If the weight of each screw is reduced by 0.5 grams, according to the amount of 1 car, it can reduce the weight of the car by more than 1 kg.

What YAMASHINA sees as a trump card is aluminum, which weighs only about a third as much as iron. The company studied leading European cars in the field and developed aluminum screws that can replace iron products over a period of three years.

The aluminum screws also match the resin parts. It is said that in terms of shrinkage caused by thermal change, the two are very close, and the screws are not easy to loosen. YAMASHINA has developed products for carbon fiber reinforced composite (CFRP), which is considered a new generation of materials. The company believes that "with the diversification of materials, the use of aluminum screws will also increase" (Furukawa Taji).

On the other hand, Maruemu Works, a screw manufacturer in Oto City, Osaka Prefecture, is vigorously developing titanium screws. This screw has a strong resilience in the face of tension, and the shaft of the screw will expand like a spring, so it is not easy to loosen when it is strongly shaken. It is expected to be used in areas where safety requirements are particularly high in pure electric vehicles.

The bottleneck is that the material cost is 30 times that of iron, and the processing is difficult. Maruemu Works also successfully mass-produced magnesium alloy screws for the first time in the world, and has the technical capability to handle different materials. Tajima President Naoyuki said, "We will establish mass production technology by 2022 and provide products at a price suitable for relevant purposes."

If you can't keep up with the trend of pure electric vehicle transformation, the screw industry will also be hit. In fact, there has been a trend of using adhesives and thermal welding technology outside Japan.

"The screws will not disappear," says Chiaki Sato, a professor at Tokyo Institute of Technology who specializes in joining auto parts. But he also believes that pure electric vehicles often need to tighten parts in small Spaces, "in order to prevent loosening, etc., the use of adhesives will increase." Screws need to evolve.