Toyota confirmed that it has used aluminium with falsified strength and durability ratings in its doors and other outer areas. "We recognize that this breach of compliance principles on the part of a supplier is a grave issue".
Smaller Japanese automaker Subaru said that it used Kobe Steel products not only for vehicles sold to retail customers but also in aircraft. Kobe didn't say if customers outside of the country were impacted, though Toyota said the faulty materials were only supplied to its plants in Japan.
In a new corporate scandal rocking Japan, Tokyo-based Kobe Steel admitted that it's been faking data on some of its metal - specifically copper and aluminum.
It said that the products in question have also been used in another rocket scheduled to be launched by March 2018.
Boeing also could be impacted through another company, Japan's IHI produces some engines for the US aircraft giant and also uses some Kobe Steel products.More news: Nadal eases past Kyrgios to claim China crown
Suzuki Motor and Mitsubishi Motors said they were checking whether their vehicles were affected. The rocket cleared all safety checks before launch, the company said.
Kobe Steel's aluminium and copper operations account for about 20% of total sales, according to data for the quarter ended June 30. "If the aluminium business doesn't work out well, I question where the company can make money", given that profitability at the mainstay steel business remained low, he said.
"These are improper actions that could shake the foundation of fair trade", Yasuji Komiyama, director of the industry ministry's metal industries division, told reporters at a briefing on the revelations. "We urge the company to make efforts to recover the trust of society as a whole, not just its customers".
The false data supplied to automakers was meant to make metals look like they met clients' quality standards.
Takata, whose problematic airbags have been blamed for more than a dozen deaths, pleaded guilty in the United States in February for misleading automakers about the safety of the airbags.
"With a string of negative surprises at Kobe Steel lately, we believe investors are likely to distrust management even more due to this latest incident, despite emerging signs of earnings improvement in the steel and construction machinery segments", JPMorgan's Mori wrote.