Basis of Presentation	6 Months Ended
Jun. 30, 2025
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Note 1 - Basis of Presentation The accompanying unaudited Consolidated Financial Statements have been prepared by Metallus Inc. (the “Company” or “Metallus”) in accordance with generally accepted accounting principles in the United States (“U.S. GAAP”) for interim financial information. Accordingly, they do not include all of the information and footnotes required by U.S. GAAP for complete financial statements. In the opinion of management, all adjustments (consisting of normal recurring accruals) and disclosures considered necessary for a fair presentation have been included. For further information, refer to Metallus' audited Consolidated Financial Statements and Notes included in its Annual Report on Form 10-K for the year ended December 31, 2024.

The entire disclosure for the basis of presentation and significant accounting policies concepts. Basis of presentation describes the underlying basis used to prepare the financial statements (for example, US Generally Accepted Accounting Principles, Other Comprehensive Basis of Accounting, IFRS). Accounting policies describe all significant accounting policies of the reporting entity.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 235
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org/235/tableOfContent

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