Worthington Steel, Inc. 8-K/ACurrent Reports (8-K / ad hoc)

Changes / Accountants

Item 9.01 Financial Statements and Exhibits. (a) Financial Statements of Businesses Acquired. The following financial statements of Klöckner & Co SE are filed as exhibits to this Form 8-K/A and are incorporated herein by reference: • Exhibit 99.1: Financial statements of Klöckner & Co SE consisting of: • Audited consolidated financial statements as of and for the fiscal year ended December 31, 2025 and 2024, including the report of independent auditors thereon; and • Unaudited condensed consolidated interim financial statements as of and for the three months ended March 31, 2026 and 2025. The financial statements described above are being filed pursuant to Rule 3-05 of Regulation S-X. (b) Pro Forma Financial Information. The following unaudited pro forma condensed combined financial information is filed as an exhibit to this Form 8-K/A and is incorporated herein by reference: • Exhibit 99.2: Unaudited pro forma condensed combined financial statements of Worthington Steel, Inc. giving effect to the Acquisition, consisting of: • Unaudited pro forma condensed combined balance sheet as of February 28, 2026; and • Unaudited pro forma condensed combined statement of earnings for the year ended May 31, 2025 and for the nine months ended February 28, 2026. (d) Exhibits. Exhibit No. Document Description 99.1 Klöckner & Co SE Audited Consolidated Financial Statements as of and for the fiscal year ended December 31, 2025 and 2024 and Unaudited Condensed Consolidated Interim Financial Statements as of and for the three months ended March 31, 2026 and 2025 99.2 Worthington Steel, Inc. Unaudited Pro Forma Condensed Combined Balance Sheet as of February 28, 2026 and the Unaudited Pro Forma Condensed Combined Statements of Earnings for the Year Ended May 31, 2025 and for the Nine Months Ended February 28, 2026 104 Cover Page Interactive Data File (embedded within the Inline XBRL document) SIGNATURES Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized. WORTHINGTON STEEL, INC. Date: August 19, 2026 By: /s/ Joseph Y. Heuer Name: Joseph Y. Heuer Title: Vice President - General Counsel and Secretary