The filings, first reported by German magazine WirtschaftsWoche, have been made by Thyssenkrupp Presta Danville LLC, which requires assembled camshaft tubes, and U.S. subsidiaries of Voestalpine.

"Voestalpine (U.S.) companies (which import the steel) have already submitted numerous applications for exemptions from the announced U.S. punitive tariffs on their products. The bureaucratic effort has proven to be very high," a spokesman for the Austrian steelmaker said in e-mailed comments.

He said none of the applications have been approved so far.

U.S. President Donald Trump has imposed import duties of 25 percent on steel and 10 percent on aluminium on grounds of national security, but granted European Union producers a temporary exemption until June 1 pending the outcome of ongoing negotiations.

(Reporting by Christoph Steitz, Tom Kaeckenhoff and Alexandra Schwarz-Goerlich. Editing by Jane Merriman)

Stocks treated in this article : thyssenKrupp, voestalpine AG