Nippon Steel said it had filed patent infringement lawsuits against Toyota and China’s Baoshan Iron & Steel with a Tokyo district court.

Nippon Steel is seeking JPY20bn (US$176m) in damages from each company, alleging the two firms have infringed on its patents on non oriented magnetic steel sheets that are used in electric vehicles, it said in a statement cited by Reuters.

Discover B2B Marketing That Performs

Combine business intelligence and editorial excellence to reach engaged professionals across 36 leading media platforms.

Find out more

Toyota said in a statement to Reuters the suit was “very regrettable” and that it had found no patent infringement issues before it signed a supply deal with the steelmaker.

A Baosteel spokesperson had no immediate comment to the news agency.

In a rare lawsuit against its key customer, Nippon Steel has also filed a petition for a preliminary injunction prohibiting Toyota from manufacturing and selling motor driven vehicles which use the electrical steel sheets allegedly violating its patents.

“The electrical steel sheets are indispensable materials for automobile electrification and are one of our key products aimed at helping decarbonisation for cars, electrical products and power plants” a Nippon Steel spokesperson said.

The company had decided to take legal action as it could not reach a resolution through discussions with both companies, it said.

This was the first time Nippon Steel had filed a patent infringement lawsuit against Toyota, the spokesperson added.

The steelmaker declined to give further details to Reuters, including the names of the Toyota products and the size of their sales.

Just Auto Excellence Awards - Nominations Closed

Nominations are now closed for the Just Auto Technology Excellence Awards. A big thanks to all the organisations that entered – your response has been outstanding, showcasing exceptional innovation, leadership, and impact.

Excellence in Action
Continental has secured the Window Displays Innovation Award in the 2025 Just Auto Excellence Awards for its Window Projection solution, transforming side windows into dynamic, data-rich canvases. Discover how this compact projection technology and intelligent software are reshaping in-car UX and opening fresh revenue streams for OEMs and mobility providers.

Discover the Impact