Kobe Steel has not released the names of the manufacturers that received the affected goods, nor whether any of its own products might have incorporated them.
Meanwhile, Mazda said it used aluminium made by Kobe in vehicle bonnets.
Japan's famous "Shinkansen" bullet trains also used Kobe Steel's aluminium, as did high-speed trains in Britain, according to engineering firm Hitachi. A senior government official said managers at Kobe Steel were involved in fabricating data on products used in planes, trains and automobiles, but Kawasaki said his current priority is to deal with safety checks with its clients.
Apan's Kobe Steel Ltd plunged deeper into crisis on Wednesday as fresh revelations showed data fabrication at the steelmaker was more widespread than initially thought, heightening a safety scare along the global supply chain.
Since then the embattled firm has seen its shares plunge almost 40% - wiping more than $1.5bn (£1.1bn) off its market value.
Kobe Steel also said it had found a case of data falsification in its iron powder products and 70 cases at its Kobelco Research unit. "It seems in some cases quality control was undertaken by veteran employees who had lots of experience, highly trusted within the organisation, and somehow these discrepancies slipped by them", company spokesperson Gary Tsuchida said. It was not clear whether the scandal affected the safety of their products.
Mr. Kawasaki, the Kobe Steel president, spoke on Thursday after a meeting with officials from the Japanese Ministry of Economy, Trade and Industry, which regulates steel makers.
In 2015, it was revealed that Toyo Tire & Rubber fabricated data to secure government approval for materials to absorb shocks from earthquakes.
Toshiba Corp is still battling the fallout of a scandal involving reporting inflated profits.
The corrosive business practices have raised broader questions over corporate governance in Japan, and cast doubt on the integrity of a manufacturing industry once the envy of the world.
Kobe Steel said the misconduct involved dozens of staff and possibly stretched back 10 years. Its customers include Toyota Motor, General Motors and Ford, as well as aircraft manufacturers like Boeing and Mitsubishi Heavy Industries.
Kobe Steel shares closed at the limit low after being untraded for the whole session, diving 22 percent to 1068 yen. Kobe Steel said it had failed to carry out tests it had agreed to conduct, and improperly "rewrote" inspection data.
In a statement on Wednesday, Kobe Steel denied a Nikkei business daily report that it meant to put its real estate business up for sale to help shore up its finances.
In a statement on Sunday Kobe Steel said some aluminum and copper products shipped from September 2016 to August 2017 were falsely labeled.