Between July 2020 and November 2021, NLMK 's exemption requests were denied amid objections from the US steelmakers United States Steel Corporation, AK Steel Corporation (currently Cleveland-Cliffs) and Nucor Corporation, claiming that they can supply suitable substitutes for NLMK 's slab needs. While the US mills are producing slabs with a thickness of 200 mm, NLMK needs material with a thickness of 250 mm. The US DOC decided to reject the exemption requests on the basis that the US mills could supply slab which was either identical or a suitable substitute. NLMK is challenging the DOC's basis for the denials, which is that the US mills could timely produce substitute slab in sufficient quantity and quality, and suggests that it needs further explanation. The company also asked the court to refund the $255 million it has paid in Section 232 tariffs, though this request was denied by the CIT.