The gaskets and packings were all produced at a facility operated by subsidiary Mitsubishi Cable Industries Ltd (MCI) in Minoshima, Japan.
The products are mainly used to prevent leakage of oil, water and air in aerospace, automotive and industrial-equipment applications, a Mitsubishi Materials statement explained.
A quality audit at the MCI works found that inspection data had been rewritten “so that the measurements and/or materials composition of seal products fell within the range of customer or internal company specifications.”
Mitsubishi Materials’ subsequent evaluation of products delivered between 1 April 2015 and 30 Sept 2017 identified around 270 million non-conforming product units, worth around Yen6.8 billion (€51 million).
These products, it stated, had gone to 70 end users in the aerospace sector as well as 25, 12 and 7 respectively in the industrial equipment, electrical power and automotive industries. There were also 115 affected customers listed in an ‘others’ category.
The group noted that MCI had delivered a total of 1.33 billion sealing product units during the evaluation period. Seals, it added, represented 40% of MCI’s sales of Yen29.5 billion in its fiscal 2016.
The Japanese group announced that similar irregularities were discovered at two other of its subsidiaries, Mitsubishi Shindoh and Mitsubishi Aluminium.
This, the latest in a series of scandals to hit Japanese manufacturing industry, follows on from Kobe Steel’s admission of misreporting of product data at a number of its subsidiary companies.