Proxy Statement (Form DEF 14A)

Dear Shareholders,

Metallus Inc. invites you to attend its 2025 annual meeting of shareholders at 10 a.m. EDT on May 7, 2025. We will consider matters that are important to our company and to you, our investors.

Weak market demand across many of our end markets in 2024 drove lower ship tons and utilization rates, resulting in financial results well below expectations for 2024. Over the past few years and with a focus on continuous improvement, we have structurally enhanced our business to be more resilient against economic downturns such as those experienced in 2024. As a result, despite challenging market conditions, we delivered positive net income and operating cash flow in 2024 while maintaining a strong balance sheet and returning capital to shareholders through our share repurchase program.

This year underscored the importance of focusing on what we can control - namely investing in our people and our assets and nurturing our valued partnerships with our customers and suppliers. Throughout the year, our team remained focused on maintaining and investing in our world-class assets aimed at improving safety, quality and efficiency. In addition, we continued to provide training and development opportunities for our employees. We believe these actions are not only critical for our long-term growth but will help us emerge from the current downtustronger and ready to capitalize on opportunities as market conditions improve.

In 2024, Metallus entered into an agreement with the U.S. Army for $99.75 million in funding to support their mission of increasing munitions production for national security in the upcoming years, as well as an agreement for $3.5 million in grants from JobsOhio. The agreements support the commissioning of two major assets: a continuous bloom reheat furnace and a roller hearth heat treat furnace. These assets are expected to enhance production capacity, improve processing efficiencies, increase first-time quality, and reduce yield loss, benefiting all our customers. The company received $53.5 million of the funding in 2024, with additional funding expected throughout 2025 and into early 2026 as mutually agreed upon milestones are achieved. The confidence placed in us by the U.S. Department of Defense has proudly established Metallus as a key materials supplier.

As we conduct our business, we consistently prioritize safety, which remains a core value at Metallus. In 2024, we spent approximately $8 million on safety equipment and comprehensive training programs company-wide, covering critical areas such as machine guarding upgrades, hand safety practices and training to prevent serious injuries or fatalities. Our goal is to ensure that our employees end each day injury and incident free. As a reminder, a significant portion of the annual incentive for each leader in our organization is tied directly to achieving specific safety targets.

In 2024, our teams made significant strides not only in safety but in other areas that we believe will drive long-term shareholder value, including:

We remain committed to delivering value to our shareholders, as demonstrated by our capital allocation strategy which includes strategic reinvestment in our business and our ongoing share repurchase program. In 2024, the company invested $64.8 million in capital expenditures and deployed $54.8 million for shareholder retuactivities, further reducing diluted shares outstanding.

Despite the challenging market conditions we faced in 2024, Metallus reported 2024 net sales of $1.1 billion and recorded net income of $1.3 million, with adjusted EBITDA of $77.7 million⁽¹⁾ and operating cash flow of $40.3 million.

Looking ahead, our focus will continue to be on safety, exceptional customer service and advancing our strategic imperatives to drive sustainable profitability and cash flow in all market conditions. We are deeply grateful to our employees for their commitment and teamwork, our customers for their consistent trust, our reliable suppliers for their strong partnerships and our shareholders for their ongoing trust and support.

Sincerely,

March 13, 2025

Enclosure

Notice of annual meeting

of shareholders

Important notice regarding the availability of proxy materials for the 2025 annual meeting of shareholders to be held on May 7, 2025: This proxy statement and our 2024 annual report to shareholders are available free of charge on the following website: www.proxydocs.com/mtus.

If you have not already done so, please consider signing up to receive proxy materials electronically by following the instructions when you vote your shares over the internet. Enrolling in electronic delivery reduces printing and mailing expenses and environmental impact.

Additional information

To register to attend the virtual annual meeting, please follow these instructions:

Registered Shareholders: If your shares are registered in your name with the company's transfer agent or you are a participant holding Metallus shares in a 401(k) plan sponsored by Metallus and you wish to attend the virtual meeting, go to www.cesonlineservices.com/mtus25_vm. Please have your proxy card or notice of internet availability containing your 11- digitcontrol number available and follow the instructions to complete your registration request. After registering, you will receive a confirmation email with a link and instructions for accessing the virtual annual meeting. Requests to register to participate in the virtual annual meeting must be received no later than 10 a.m. EDT on May 6, 2025.

Beneficial Shareholders (those holding shares through a stock brokerage account or by a bank or other holder of record): Beneficial shareholders who wish to attend the virtual meeting may register by visiting the website www.cesonlineservices.com/mtus25_vm. Please have your voting instruction form, notice or other communication containing your control number available and follow the instructions to complete your registration request. After registering, you will receive a confirmation email with a link and instructions for accessing the virtual annual meeting. Requests to register to participate in the virtual annual meeting must be received no later than 10 a.m. EDT on May 6, 2025.

If you do not register in advance following the instructions above, you will not be able to attend the annual meeting. If you need assistance registering, please contact our proxy solicitor, Innisfree M&A Incorporated, toll-freeat (888) 750-5834.The annual meeting will begin promptly at 10 a.m. EDT on May 7, 2025. We encourage you to access the annual meeting prior to the start time. Online access will begin at 9:30 a.m. EDT.

The virtual annual meeting platform is fully supported across browsers (Microsoft Edge, Firefox, Chrome and Safari) and devices (desktops, laptops, tablets and cell phones) running the most updated version of applicable software and plugins. Participants should ensure they have a strong internet connection wherever they intend to participate in the annual meeting. Participants also should allow plenty of time to log in and ensure that they can hear streaming audio prior to the start of the annual meeting.

In order to maintain the interactive nature of the virtual meeting, attendees will be able to vote during the annual meeting by clicking on the 'Shareholder Ballot' link located under the 'Meeting Links' section of the virtual meeting website.

If you wish to submit a question to be addressed at the annual meeting, please do so by submitting your question to [email protected]in advance of the meeting. Questions will be accepted until 12 p.m. EDT on May 6, 2025.

Questions submitted by shareholders in accordance with the foregoing instructions and pertinent to the annual meeting will be answered during the annual meeting, subject to time constraints. We will respond to questions relevant to meeting matters that we do not have time to address during the meeting by posting the questions and answers on our investor relations website soon after the meeting. Questions regarding personal matters or matters not relevant to meeting matters will not be answered. Additional information regarding the ability of shareholders to ask questions during the annual meeting, related rules of conduct and other materials for the annual meeting will be available online during the meeting.

Even if you plan on attending the virtual annual meeting, we encourage you to vote your shares in advance using one of the methods described in this proxy statement to ensure that your vote will be represented at the annual meeting.

Technical Difficulties: If you experience any technical difficulties during the registration process, please access the 'FAQ and System Test' link on the login screen for support. If you experience technical difficulties during the virtual meeting, please access the '?' link on the meeting website for support. In the event of technical difficulties with the virtual annual meeting, we expect that an announcement will be made on www.cesonlineservices.com/mtus25_vm. If necessary, the announcement will provide updated information regarding the date, time and location of the annual meeting. Any updated information regarding the annual meeting will also be posted on our investor relations website at www.metallus.com.

Table of Contents

Although we include references to our website throughout this proxy statement, information contained on or accessible through, including any reports available on, our website is not a part of, and is not incorporated by reference into, this proxy statement or any other report or document we file with the Securities and Exchange Commission ("SEC"). Any reference to our website throughout this proxy statement is intended to be an inactive textual reference only. "Material" or "materiality," as used in the "Our commitment to sustainability" section, should not be read as equating to any use of the word in our other reporting or filings with the SEC.

Certain statements set forth in this proxy statement (including our forecasts, beliefs and expectations) that are not historical in nature are "forward-looking" statements within the meaning of the Private Securities Litigation Reform Act of 1995. Forward-looking statements generally will be accompanied by words such as "anticipate," "aspire," "believe," "could," "estimate," "expect," "forecast," "outlook," "intend," "may," "plan," "possible," "potential," "predict," "project," "seek," "should," "strategic direction," "strategy," "target," "will," "would," or other similar words, phrases or expressions that convey the uncertainty of future events or outcomes. You are cautioned not to place undue reliance on forward-looking statements, which speak only as of the date of this proxy statement. We caution readers that actual results may differ materially from those expressed or implied in forward-looking statements made by or on behalf of us due to a variety of factors, such as:

You are cautioned that it is not possible to predict or identify all of the risks, uncertainties and other factors that may affect future results, and that the above list should not be considered to be a complete list. Except as required by the federal securities laws, we undertake no obligation to publicly update or revise any forward-looking statement, whether as a result of new information, future events or otherwise.

Further, information included in this proxy statement represents our current policy and intent and is not intended to create legal rights or obligations. Certain standards of measurement and performance contained in this proxy statement are developing and based on assumptions, and no assurance can be given that any plan, objective, initiative, projection, goal, target, mission, commitment, expectation, or prospect set forth in this proxy statement can or will be achieved. Inclusion of information in this proxy statement is not an indication that the subject or information is material to our business or operating results.

Proxy summary

This summary highlights information contained elsewhere in this proxy statement and contains only a portion of the information you should consider. You should read the entire proxy statement carefully before voting.

Our annual meeting

Director nominees

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Board skills and composition

Our directors and director nominees possess a broad mix of executive leadership, strategic, financial, human resources, sustainability and industry experience and skills that enable them to effectively oversee the management of the business and drive strategy that creates long-term, sustainable shareholder value.

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2024 performance

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Sustainability highlights

At Metallus, our sustainability strategy reflects our vision to harness the enduring power of high-performance metals to make the world a better place. We focus on creating long-term shareholder value by employing sustainable practices. Our commitment to operating responsibly helps ensure we create and maintain a safe and healthy workplace, protect our natural resources and deliver sustainable technologies that contribute to economic growth and prosperity.

With oversight of our sustainability strategy provided by our full Board of Directors, we are committed to making progress towards our long-term goals by addressing areas where we can have the most impact. We report on sustainability metrics, in reference to the Global Reporting Initiative (GRI) standards, including providing disclosures in accordance with the Sustainability Accounting Standards Board (SASB) for our sector and informed by the Task Force on Climate-related Financial Disclosures (TCFD). Our 2024 sustainability update, which we expect to release in April 2025, will also reference GRI standards and will align with the SASB Standard for Iron & Steel Producers sector. We believe regular, transparent communication with stakeholders about key areas of focus and our progress against established goals is pivotal to our success. See "Our commitment to sustainability" for additional information regarding oversight and risk management and the pillars and focus areas of our sustainability program.

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The company's 2030 targets for greenhouse gas (GHG) emissions, energy consumption and fresh water withdrawn are based on an absolute or total reduction in the amount of GHG emissions, energy consumption and fresh water withdrawn as compared to a 2018 baseline. In contrast, the company's waste-to-landfilltarget is based on an intensity or percentage reduction of waste-to-landfillper ton of steel shipped as compared to a 2018 baseline. All 2030 targets are based on the company's operating assets as of 2018 and do not account for any future inorganic growth or other expansion of its facilities or operating assets, for which an adjustment to the absolute reduction may be required. The company selected 2018 as the baseline year as it aligns with the baseline used in the company's Sustainability Accounting Standards Board (SASB) disclosure. Following the publication of steel sector guidance and standards in 2023 by the Global Steel Climate Council (GSCC), the company has evaluated its existing goals and performance. The company intends to submit a science-based target aligned with the GSCC's Steel Climate Standard for validation by an accredited third-party organization, which may result in refreshed environmental goals.

The company's 2030 targets are supported by projects across the company's manufacturing, supply chain and corporate operations and, in 2021, the indefinite idling of the company's Harrison melt and casting assets contributed to the reduction in greenhouse gas emissions. We have allocated approximately $3 million of capital expenditures per year through 2030 to achieve our long-term sustainability goals, including safety- and environmental-related projects. In 2024, actual capital expenditure spend was approximately $2.8 million related to these initiatives, which primarily related to safety projects.

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Our employees are critical to our success and are the reason we are able to execute at a high level. We believe a continuous focus on company culture and employee engagement will help us provide high quality products to our customers. In 2024, we conducted semi-annual surveys to gather insight into the level of employee engagement at Metallus and other factors that contribute to a successful workplace. These surveys help to ensure we are continuously listening to our employees and measuring our progress. We regularly communicate with our employees regarding survey results and actions being taken in response.

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Aligning pay with performance

Our compensation objectives and philosophy

At Metallus, our executive compensation program is designed to align our executives' interests with those of our shareholders; to reward leaders for strong business results; and to attract, retain and motivate the best talent in the industry.

Our executive compensation philosophy embodies the following principles:

✓ Recognizes people are our strongest assets

✓ Rewards results linked to short- and long-term performance (pay-for-performance)

✓ Positions pay affordably and competitively in the marketplace

✓ Drives a focus on increasing shareholder value

2024 target pay mix

In support of our pay-for-performancephilosophy, a substantial majority of the target total direct compensation for our named executive officers ("NEOs") under our annual compensation program is allocated to variable compensation. The compensation structure for Mr. Williams is weighted even more significantly towards variable and performance-based compensation, with 82 percent of his target total direct compensation designed to be at risk as variable compensation. The pie charts below show, for our CEO and, on average, our other NEOs, the mix of aggregate compensation at target for 2024 under our annual compensation program.

Pay and performance at a glance

The compensation of our NEOs during 2024 reflects our financial results both for the current year and the three-year period ended December 31, 2024, and demonstrates that our compensation plans pay for performance as intended. While base pricing remained relatively steady throughout the year, customer demand was weak across the industrial and energy markets as well as the distribution channel. As a result,

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customer shipments were below expectations and melt utilization was below optimal levels, resulting in profitability below the threshold performance objective established for 2024 and adjusted operating cash flow which, while above threshold, was still well below the target performance objective for 2024. This resulted in no payout on the adjusted EBITDA metric and a payout (on an unweighted basis) of 19.0 percent of target on the adjusted operating cash flow metric.

To reinforce the strategic importance of improving the company's safety culture and performance and drive accountability at the highest levels of the company, safety metrics comprised 20 percent of the 2024 annual incentive opportunity for our NEOs. The safety metrics included typical lagging indicators (comprising 40 percent of the safety metric) for OSHA recordable and lost time incident rates and a leading indicator (comprising 60 percent of the safety metric) for timely completion of corrective actions related to near miss incidents which have the potential to result in a serious injury or fatality (referred to as the PSIF action completion rate). While the company's OSHA lost-time incident rate and OSHA recordable rate each failed to achieve the threshold performance objective for 2024, the company continued to make significant improvements year-over-year with respect to the PSIF action completion rate, surpassing the maximum performance objective established for 2024. Overall, the company's safety performance in 2024 resulted in a payout percentage (on an unweighted basis) on the safety metric of 120.0 percent of target.

Based on this performance, the Compensation Committee approved a total payout of 29.7 percent of target for each NEO based on performance against the metrics established for the 2024 APA plan.

For the performance shares awarded for the 2022-2024 performance cycle, NEOs earned a payout of 80.0 percent of the target number of performance shares granted, based on the company's relative total shareholder retuas compared to an identified peer group of steel companies for the one-,two-and three-year periods beginning January 1, 2022 and ended December 31, 2022, 2023 and 2024. Relative total shareholder retufor the first performance period ended December 31, 2022 was achieved at the 44^th percentile of the identified peer group, and relative total shareholder retufor the second performance period ended December 31, 2023 was achieved at the 43^rd percentile of the identified peer group. For the third and final performance period ended December 31, 2024, relative total shareholder retuwas achieved at the 33^rd percentile of the identified peer group, with Metallus delivering a cumulative total shareholder retuof approximately 2.3 percent for the January 1, 2022 - December 31, 2024 performance period. The below-target payout earned for the 2022-2024 performance cycle, combined with a decrease in the

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company's share price from $17.74 at the March 1, 2022 grant date to $14.13 at the December 31, 2024 conclusion of the performance period, resulted in a total realized payout to participating NEOs equal to approximately 63.7 percent of the target value of the 2022-2024 performance share award.

See "Compensation Discussion and Analysis - Analysis of 2024 compensation" for additional information.

Looking ahead in 2025

In 2024, shareholders approved the compensation of our NEOs with approximately 99 percent of votes cast in favor of our "say-on-pay"proposal. Our Compensation Committee considered the results of this vote, the changes made to executive compensation programs in recent years, shareholder feedback and market data in its annual review of our executive compensation plans. Based on this evaluation, for 2025 the Compensation Committee has determined to continue to focus the annual incentive plan on profitability, cash flow generation and safety, and to continue to use relative total shareholder return, measured for the one-,two-and three-year periods within a three-year performance cycle, as the metric for the performance shares awarded under the company's long term incentive plan.

With respect to the long-term incentive plan, the Committee has determined that all long-term incentive grants made in 2025 will continue to be in the form of performance shares and time-based restricted stock units, with the long-term incentive mix for Mr. Williams remaining approximately 60 percent performance shares and 40 percent time-based restricted stock units, and the long-term incentive mix for the other NEOs remaining approximately 50 percent performance shares and 50 percent time-based restricted stock units.

Finally, in connection with the annual review of the compensation of the company's President and CEO, in February 2025 the Compensation Committee recommended and the Board approved for Mr. Williams an increase in (i) annual base salary from $875,000 to $910,000, (ii) the target annual incentive opportunity (as a percentage of base salary) from 100 percent to 110 percent and (iii) the target value of awards under the company's long-term incentive plan from $3.25 million to $3.35 million annually. The Compensation Committee's recommendation was based primarily on a finding that the current target total direct compensation for Mr. Williams fell below the market median (as compared to peer group compensation data provided by the Committee's independent compensation consultant, Meridian Compensation Partners, LLC ("Meridian")).

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Proposal 1

Election of directors

The company currently has eleven members on its Board of Directors, divided into three classes for purposes of election, with three-year terms of office ending in successive years. The term of office of the Class II directors expires at the 2025 annual meeting. The Board of Directors has nominated each of Kenneth V. Garcia, Ellis A. Jones, Melissa M. Miller and Donald T. Misheff for election as a director at the 2025 annual meeting of shareholders, to serve for a term of three years expiring at the 2028 annual meeting of shareholders or until his or her successor is duly elected and qualified (or until his or her earlier death, resignation or removal). Ms. Miller and Messrs. Garcia, Jones and Misheff each currently serves as a director and has agreed to continue serving if elected.

If any of the nominees is unable to stand for election, the Board of Directors may designate a substitute. Shares represented by proxies may be voted for the substitute but will not be voted for more than four nominees. Directors are elected by a plurality of the votes cast. The four nominees receiving the greatest number of votes will be elected.

Pursuant to the majority voting policy of the Board of Directors, as set forth in its Corporate Governance Guidelines, any director who receives a greater number of "withhold" votes than votes "for" his or her election in an uncontested election will submit his or her resignation to the Board of Directors promptly after the certification of the election results. The Nominating and Corporate Governance Committee will consider and provide its recommendation to the Board of Directors regarding, and the Board of Directors will then consider and act upon, the tendered resignation in light of any factors they consider appropriate, including the director's qualifications and contributions to the Board of Directors, as well as any reasons given by shareholders regarding why they withheld votes from the director. The Board of Directors is required to determine whether to accept or reject the tendered resignation within 90 days following the election and to promptly disclose its decision, as well as the reasons for rejecting any tendered resignation, if applicable.

Holders of Metallus common shares are entitled to cast one vote for each share held on the record date for up to four nominees for director. A shareholder may not cumulate his or her shares in voting for director nominees. For example, a shareholder who owns 100 Metallus common shares may vote 100 shares for each of the four nominees. The shareholder may not, however, vote more than 100 shares for any one nominee, or vote for more than four nominees.

Shares represented by proxy will be voted FOR these nominees unless specified otherwise in the voting instructions.

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Our knowledgeable Board of Directors

Our directors and director nominees have diverse sets of skills, qualifications and experiences that enable them to effectively oversee the management of the company's business affairs. Our directors represent the interests of Metallus' stakeholders and help to drive strategic decisions for the company's long-term success.

Biographical information on each of the nominees and a description of his or her qualifications to serve as a director, as well as similar information about the other directors whose terms will continue following the annual meeting, are provided in the pages that follow. All information is as of February 28, 2025, unless otherwise indicated.

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Nominees for election as Class II directors to serve a three-year term expiring at the 2028 annual meeting of shareholders

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Board of directors information

Meetings and committees

During calendar year 2024, there were eight meetings of the Board of Directors. All incumbent directors attended 75 percent or more of the aggregate number of meetings of the Board and its committees on which they served. It is our policy that all members of the Board of Directors serving at the time of the annual meeting of shareholders should attend the annual meeting, and all such directors attended the 2024 annual meeting of shareholders. The independent directors met separately in executive session without management present at least quarterly in conjunction with regularly scheduled meetings of the Board in 2024 and intend to meet separately in executive sessions without management present at least quarterly in conjunction with regularly scheduled meetings of the Board of Directors in 2025 and thereafter.

The standing committees of the Board of Directors consist of the Audit Committee, the Compensation Committee and the Nominating and Corporate Governance Committee. Each of these committees meets regularly and has a written charter approved by the Board of Directors which is reviewed and reassessed annually. A current copy of each of these charters is available on the company's website at www.metallus.com. At each regularly scheduled Board meeting, the Chair of each committee reports on any significant matters addressed by the committee since the last regularly-scheduled Board meeting.

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Audit Committee report

The Audit Committee has reviewed and discussed with management and the company's independent auditor the audited financial statements contained in the company's Annual Report on Form 10-Kfor the fiscal year ended December 31, 2024, as well as the critical audit matter addressed in the audit and the relevant financial statement accounts or disclosures that relate to the critical audit matter. The Audit Committee also has discussed with our independent auditor the matters required to be discussed by the applicable requirements of the Public Company Accounting Oversight Board ("PCAOB") and the SEC.

The Audit Committee has received and reviewed the written disclosures and the letter from our independent auditor required by applicable requirements of the PCAOB regarding the independent auditor's communications with the Audit Committee concerning independence, has discussed with the independent auditor such auditor's independence, and has considered the compatibility of any non-auditservices with the auditor's independence.

Based on the review and discussions referred to above, the Audit Committee recommended to our Board of Directors that the audited financial statements be included in our Annual Report on Form 10-Kfor the fiscal year ended December 31, 2024, filed with the SEC.

Donald T. Misheff (Chairperson)

Mary Ellen Baker

Nicholas J. Chirekos

Ellis A. Jones

Jamy P. Rankin

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With the guidance and approval of the Compensation Committee, the company has developed compensation programs for its executive officers that are intended to align the interests of our executives and shareholders; reward executives for sustained, strong business and financial results; and enable us to attract, retain and motivate the best talent.

The agenda for meetings of the Compensation Committee is determined by its chairperson with the assistance of management. The meetings are regularly attended by the President and CEO, the Executive Vice President and Chief Financial Officer, the Executive Vice President, General Counsel and Chief Human Resources Officer, the Senior Director, Human Resources and the Senior Manager, Compensation and Benefits. The Compensation Committee meets in executive session at each of its meetings, and the chairperson reports the Committee's actions regarding compensation of executive officers to the full Board of Directors. The company's human resources department supports the Compensation Committee in its duties and the Committee may delegate to the human resources department and to other company personnel certain administrative duties in connection with the company's compensation programs.

The Compensation Committee has the sole authority to retain and terminate compensation consultants to assist in the evaluation of director and executive officer compensation and the sole authority to approve the fees and other retention terms of any compensation consultants. The Committee has selected Meridian to

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serve as its independent compensation consultant. The Compensation Committee has engaged Meridian to analyze our executive compensation structure and plan designs, to assess whether the compensation program is competitive and supports the Compensation Committee's goal to align the interests of executive officers with those of shareholders and, from time to time, to review the total compensation of directors. Meridian also provides market data directly to the Compensation Committee, which the Committee references when determining compensation for executive officers. Additional information regarding the Committee's engagement of Meridian, including a discussion of the Committee's assessment of the independence of Meridian, is available in the "Compensation discussion and analysis" ("CD&A") section of this proxy statement under the caption "Determining compensation for 2024 - Role of the compensation consultant: Advising the Compensation Committee."

Compensation Committee interlocks and insider participation

As noted previously, members of the Compensation Committee currently include Kenneth V. Garcia (chairperson), Randall H. Edwards, Melissa M. Miller and Randall A. Wotring. Diane C. Creel served as chairperson and a member of the Compensation Committee until her retirement on May 7, 2024.

No director who served as a member of the Compensation Committee during 2024 is, or was during 2024, an officer or employee of the company. Further, no director who served as a member of the Compensation Committee during 2024 was formerly an officer or employee of the company. All directors who served on the Compensation Committee during 2024 were independent as defined in the listing standards of the New York Stock Exchange during their time of service. Additionally, during 2024, no member of the Compensation Committee had a relationship that is required to be disclosed under SEC rules regarding related-party transactions. Finally, no executive officer of the company serves or served on the compensation committee or board of directors of any company where any member of the Compensation Committee or the Metallus Inc. Board of Directors is, or was during 2024, an executive officer.

Compensation Committee report

The Compensation Committee has reviewed and discussed with our management the CD&A for the year ended December 31, 2024. Following and based on that review and discussion, the Compensation Committee recommended to our Board of Directors, and our Board approved, the incorporation by reference of the CD&A in the company's Annual Report on Form 10-Kfor the fiscal year ended December 31, 2024, and its inclusion in this proxy statement for filing with the SEC.

Kenneth V. Garcia (Chairperson)

Randall H. Edwards

Melissa M. Miller

Randall A. Wotring

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Director candidates recommended by our shareholders will be considered in accordance with the criteria outlined below. In order for a shareholder to submit a recommendation, the shareholder must deliver a communication by registered mail or in person to the Nominating and Corporate Governance Committee, c/o Metallus Inc., Attn: Secretary, 1835 Dueber Ave. S.W., Canton, Ohio 44706. Such communication should include the proposed candidate's qualifications, any relationship between the shareholder and the proposed candidate, and any other information that the shareholder would consider useful for the Nominating and Corporate Governance Committee to consider in evaluating such candidate.

A shareholder who wishes to nominate a person for election as a director must provide written notice to the company's secretary in accordance with the procedures specified in Article I, Sections 13 and 14 of our Code of Regulations. In general, to be timely, the written notice must be received by our secretary at our principal executive offices not less than 90 nor more than 120 days prior to the first anniversary of the date on which the company held the preceding year's annual meeting of shareholders. If the date of the annual meeting of shareholders is scheduled for a date more than 30 days prior to or more than 30 days after the first anniversary of the preceding year's annual meeting of shareholders, then a shareholder's notice must be delivered to our secretary at our principal executive offices not later than the close of business on the later of the 90th day prior to the annual meeting of shareholders or the 10th day following the day on which public announcement of the date of the annual meeting of shareholders is first made. The notice must provide certain information required by the Code of Regulations, including but not limited to (a) biographical and share ownership information of the shareholder (and certain affiliates), (b) descriptions of any material interests of the shareholder (and certain affiliates) in the nomination and any arrangements between the shareholder (and certain affiliates) and another person or entity with respect to the nomination,

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(c) biographical and employment information of each nominee, and (d) a brief description of any arrangement or understanding between each individual proposed as a nominee and any other person pursuant to which the individual was proposed as a nominee.

The Nominating and Corporate Governance Committee has utilized and expects to utilize a variety of sources to identify possible director candidates, including professional associations and Board member recommendations. In recommending candidates, the Nominating and Corporate Governance Committee considers the qualifications of candidates such as business experience and other attributes and skills, including high standards of integrity and ethical behavior, which qualify the candidate to serve as a director of the company in light of the company's business and structure. The Nominating and Corporate Governance Committee also may consider such other elements as it deems appropriate, consistent with the factors in the company's Corporate Governance Guidelines and consistent with applicable law, including but not limited to a candidate's professional background and capabilities, knowledge of specific industries, and geographic experience. The Nominating and Corporate Governance Committee also is responsible for reviewing the qualifications of, and making recommendations to the Board of Directors regarding, director nominations submitted by our shareholders. The Committee will consider all potential candidates in the same manner regardless of the source of recommendation.

The Nominating and Corporate Governance Committee periodically will review the appropriate size of the Board and plans for director succession. In the event vacancies are anticipated or arise, the Committee will consider potential director candidates. When considering potential director candidates, the Committee will assess the skills and attributes of our Board as a whole and of each individual director and evaluate whether prospective candidates possess complementary and supplementary skills and attributes that would strengthen our Board.

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Director compensation

Our non-employeedirector compensation program is intended to provide fair and competitive compensation and to align the interests of our non-employeedirectors with the interests of our shareholders. Key features of our non-employeedirector compensation program include the following:

Our non-employeedirector compensation program is reviewed periodically by the Compensation Committee and the Board to ensure that director compensation remains appropriate and competitive. In late 2023, the Compensation Committee asked Meridian (the independent compensation consultant engaged by the Compensation Committee) to conduct a competitive market analysis of the company's director compensation program relative to the same peer group of companies used by the company for benchmarking executive pay. Meridian's analysis concluded that the average annual total value of outside director compensation is positioned near median and the structure of the company's director compensation program is aligned with both peer practices and the broader market. Taking into account Meridian's analysis and conclusions, the Compensation Committee recommended, and the Board approved, continuing the compensation program for non-employeedirectors with no changes for 2024.

The compensation program under which non-employeedirectors were compensated for their services as directors during 2024 is summarized below.

Cash compensation

Each non-employeedirector is paid an annual cash retainer for services as a director. For 2024 the annual cash retainer for each non-employeedirector was set at $90,000.

An additional annual cash retainer of $90,000 was paid to the non-executiveChairman of the Board in 2024. Further, the chairperson of each standing committee of our Board of Directors was paid the following additional annual fees:

Any director also employed by the company is not paid any compensation for serving as a director.

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Stock compensation

Each non-employeedirector serving at the time of our annual meeting of shareholders receives a grant of our common shares following the meeting. The common shares are granted as restricted stock units that generally will vest on the first anniversary of the grant date. For 2024, the approximate target value of the grant for each non-employeedirector was $120,000.

A non-employeedirector who is first elected to the Board after the date of the annual meeting will receive a grant of restricted stock units at the time of his or her election to the Board. These restricted stock units generally will vest on the first anniversary of the grant date.

The company requires that the common shares granted to a non-employeedirector be held for as long as the director remains on the Board. In addition, the Compensation Committee of the Board of Directors has adopted stock ownership guidelines that require non-employeedirectors to own common shares with a value equal to five times the director's annual cash retainer. The company considers all shares owned by the director, plus unvested restricted stock units, in determining whether the director has met the ownership guidelines. As of February 28, 2025, each of the non-employeedirectors (except Messrs. Chirekos and Jones and Mses. Baker, Miller and Rankin, each of whom was appointed as director within the last four years) had achieved his or her ownership requirement.

Compensation deferral

Any non-employeedirector may elect to defer the receipt of all or a specified portion of his or her cash and/or stock compensation in accordance with the provisions of the company's Amended and Restated Director Deferred Compensation Plan. Pursuant to the plan, cash fees can be deferred and paid at a future date elected by the director. The deferred amount will be adjusted based on investment crediting options, which include interest earned quarterly at a rate based on the prime rate plus one percent or the total shareholder retuof our common shares, with amounts paid in cash either in a lump sum or in installments, as elected by the director. Stock compensation can be deferred to a future date and is payable, in a lump sum or installments, in shares plus an amount representing dividend equivalents, if any dividends are declared during the deferral period.

2024 Director compensation table

The following table provides details of non-employeedirector compensation in 2024:

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Looking ahead to 2025

In late 2024, the Compensation Committee again asked Meridian to conduct a competitive market analysis of the company's director compensation program relative to the same peer group of companies used by the company for benchmarking executive pay. Meridian's analysis concluded that the average annual total value of outside director compensation is slightly below median but the structure and design of the company's director compensation program remains well-aligned with both peer practices and the broader market. Taking into account Meridian's analysis and conclusions, the Compensation Committee recommended, and the Board approved, continuing the current compensation program for non-employeedirectors with no changes for 2025.

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Our commitment to sustainability

At Metallus, our sustainability strategy reflects our vision to harness the enduring power of high-performance metals to make the world a better place. We focus on creating long-term shareholder value by employing sustainable practices. Our commitment to operating responsibly helps ensure we create and maintain a safe and healthy workplace, protect our natural resources and deliver sustainable technologies that contribute to economic growth and prosperity.

With oversight of our sustainability strategy provided by our full Board of Directors, we are committed to making progress towards our long-term goals by addressing areas where we can have the most impact. We report on sustainability metrics, including providing disclosures in accordance with Global Reporting Initiative (GRI) standards and the Sustainability Accounting Standards Board (SASB) for our sector, and informed by the Task Force on Climate-related Financial Disclosures (TCFD). We believe regular, transparent communication with stakeholders about key areas of focus and our progress against established goals is pivotal to our success.

Metallus' sustainability strategy consists of three focus areas organized around environmental, social and governance priorities:

Sustainability update disclosures

Metallus publishes an annual sustainability update, which supplements our 2022 Sustainability Report, available on the Sustainability page on our website at www.metallus.com. This section includes a summary of the update, including an overview of our approach to sustainability governance and risk management, an explanation of our sustainability priorities and progress towards our goals associated with those priorities.

In April 2025, Metallus expects to publish its 2024 sustainability update including GRI and SASB disclosures.

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Investor outreach and shareholder engagement

We value the input we receive from our shareholders. Throughout the year, management continually engages with investors in several ways, including in-personand virtual meetings, quarterly investment calls, and investor conferences and presentations. We conduct open and transparent discussions on a variety of relevant matters, which may include corporate governance topics, our executive compensation program and sustainability initiatives, among other matters. Shareholder feedback helps guide our compensation plan and changes to our corporate governance, compensation and sustainability strategy and practices.

Our 2024 investor dialogues generally solicited positive feedback from investors with regard to the best practices reflected in our executive compensation programs and our enhanced sustainability reporting.

Sustainability oversight and risk management

Metallus' full Board of Directors oversees the company's corporate responsibility and sustainability strategy. The Board conducts an annual review of the company's sustainability strategy, risks and opportunities. The Board and its committees review information relative to the company's environmental and safety performance, as well as human resources and governance matters, on a regular basis. The following chart highlights some of these matters, including the Board and/or committee responsible and the frequency with which these matters are reviewed.

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At the management level, we have established a steering committee, comprised of senior-level leaders representing the company's legal, finance, environmental, human resources, communications, manufacturing, engineering, supply chain and commercial organizations, with responsibility for, among other matters, sponsoring, informing and advising on high priority sustainability topics through periodic materiality assessments; ensuring that goals are developed for high priority sustainability topics; and sponsoring, approving and overseeing key sustainability projects. Core working groups are then established to lead individual high priority topics and projects, under the guidance and leadership of a steering committee sponsor. This governance structure facilitates the establishment of sustainability priorities by the company's senior management team (in alignment with the strategy set by the Board of Directors), with functional area experts throughout the company responsible for leading the projects to implement the established priorities.

In 2024, the steering committee focused on the ongoing maturation of our corporate sustainability strategy, including development of standard operating procedures to ensure uniform data collection and controls over greenhouse gas (GHG) reporting and support for our large capital projects with sustainability benefits. This steering committee oversees our specialized subcommittees, responsible for implementing foundational elements of our company-wide sustainability programs and initiatives. These subcommittees promote enhanced cross-functional engagement and are organized around key topics such as data controls and procedures, external reporting, governance and strategy, sustainability projects and annual priorities and key performance indicators (KPIs).

Areas of focus

Our sustainability goals align with the environmental, social and governance topics that matter most to our stakeholders, as defined by the materiality assessment we conducted in 2021.

After collecting and analyzing responses from key stakeholders, we determined the following matters are most relevant and reasonably likely to impact the company's financial condition, operating performance, strategy and financial planning and accordingly established the following pillars and focus areas for our sustainability program.

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Environmental stewardship

2030 environmental goals

In October 2021, Metallus announced 2030 environmental goals - a critical milestone in the evolution of the company's sustainability program.

We committed to the following 2030 environmental goals, compared with a 2018 baseline:

The company's 2030 targets for greenhouse gas emissions, energy consumption and fresh water withdrawn are based on an absolute or total reduction in the amount of greenhouse gas emissions, energy consumption and fresh water withdrawn as compared to a 2018 baseline. In contrast, the company's waste-to-landfilltarget is based on an intensity or percentage reduction of waste-to-landfillper ton of steel shipped as compared to a 2018 baseline. All 2030 targets are based on the company's operating assets as of 2018 and do not account for any future inorganic growth or other expansion of its facilities or operating assets, for which an adjustment to the absolute reduction may be required. The company selected 2018 as the baseline year as it aligns with the baseline used in the company's Sustainability Accounting Standards Board (SASB) disclosure. Following the publication of steel sector guidance and standards in 2023 by the Global Steel Climate Council (GSCC), the company has evaluated its existing goals and performance. In 2024, the company became a member of GSCC, and the company intends to submit a science-based target aligned with the GSCC's Steel Climate Standard for validation by an accredited third-party organization, which may result in refreshed environmental goals.

The company's 2030 targets are supported by projects across the company's manufacturing, supply chain and corporate operations and, in 2021, the indefinite idling of the company's Harrison melt and casting assets contributed to the reduction in greenhouse gas emissions.

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We have allocated approximately $3 million of capital expenditures per year through 2030 to achieve our long-term sustainability goals, including safety- and environmental-related projects. In 2024, actual capital expenditure spend was approximately $2.8 million related to these initiatives, which primarily related to safety projects.

Social commitment

In addition to our environmental targets, we are committed to health and safety and cultivating an inclusive culture that embraces varied perspectives and talents on our Board, in leadership and throughout our company.

Health and safety

At Metallus, our core value of Safety First expresses our belief that the health and well-being of our fellow employees is essential to our ability to achieve our mission to be an industry-leading provider of high-quality specialty metals and to deliver exceptional value for our customers, employees and investors. Building and maintaining a culture of safety empowers each of us as individuals, and collectively as a company, to successfully grow. Our commitment to safety is rooted in the recognition that our personal actions affect the safety and performance of others. This sense of responsibility drives engagement through increased awareness of the vital role each team member plays in promoting a safe work environment while maintaining our commitment to best-in-classquality in our processes and products.

We recognize the need for and are committed to improving the company's safety culture. Over the past few years, we introduced new safety training focused on the core elements of improving the safety culture and performance while helping to understand the direct impact human factors have on all of us. In 2024, we built on this foundation with additional training regarding human factors which positively influence safety, performance and reliability outcomes; hand safety practices; and training to prevent serious injuries or fatalities. We invested approximately $8 million in 2024 in company-wide safety training, equipment and improved safety processes in an effort to ensure we are creating a lasting culture of safety. We expect to invest approximately $5 million in 2025 to further expand these efforts. To reinforce the importance of operating safely and responsibly, a safety metric (comprised of both leading and lagging indicators) is included in our annual incentive compensation plan for all salaried employees.

Compensation and total rewards

We provide competitive compensation programs to help meet the needs of our employees. Our programs are designed to support the profitable growth of our business; attract, reward, and retain the talent we need to succeed; support the health and overall well-being of our employees; and reinforce a performance-based culture.

In addition to base compensation, we offer quarterly and annual incentive compensation, stock awards and participation in various retirement plans. Our company also provides employer-sponsored health and wellness benefits to our employees.

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Employee retention

We seek to retain the best people by providing them with opportunities to grow, build skills and be appreciated for their contributions as they work to serve our customers. Our vision and mission inform everything we do and our work is grounded in our core values, which represent the framework on which our culture is built.

Our employees are critical to our success and are the reason we are able to execute at a high level. We believe a continuous focus on company culture and employee engagement will help us provide high quality products to our customers. In 2024, we conducted semi-annual surveys to gather insight into the level of employee engagement at Metallus and other factors that contribute to a successful workplace. These surveys help to ensure we are continuously listening to our employees and measuring our progress. We regularly communicate with our employees regarding survey results and actions being taken in response.

We diligently track our employee retention and management regularly evaluates our employees' retention risk. For 2024, we ended the year with an overall voluntary turnover rate of approximately 6 percent, comprised of approximately 4 percent for salaried and approximately 8 percent for hourly employees. This compares to an overall voluntary turnover rate of approximately 9 percent in 2023 and 16 percent in 2022. The voluntary turnover rate in 2024 was significantly improved as compared to recent years and more in line with the company's historical experience.

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Employee training and development

At Metallus, we believe that our vision moves us forward and our people drive our success. That is why it is a core component of our strategy to invest in talent and leadership development at all levels of the company. We invest significant resources to develop talent with the right capabilities to deliver the growth and innovation needed to support our business strategy. In 2024, we continued and expanded upon many of the learning and development programs introduced since 2022 and aimed at developing leadership and other professional skills and capabilities. In 2024, we also continued to build our pipeline of skilled trades talent by expanding and improving our apprentice program. We offer an educational reimbursement program to assist employees with the cost of obtaining certain undergraduate or graduate degrees. Metallus encourages our employees to constantly leaand grow and has aligned our performance management system to support this focus on continuous learning and development.

Belonging and inclusion

At Metallus, we believe our people are our strongest assets. Creating an atmosphere that provides a sense of belonging and inclusion is fundamental to our strategic imperative to attract and retain top talent and provide equal opportunities for growth to all employees. We foster a culture that lends a variety of perspectives and expertise to our operations. We recognize that an inclusive, engaging culture has enabled us to deliver innovative solutions throughout the life of our business and is key to our continued business success. Within our organization, we maintain employee resource groups (ERGs) which further promote belonging and inclusion. We have an advisory council comprised of senior leaders in the company and the executive sponsors of our ERGs to advance and champion the company's efforts to leverage our unique perspectives, backgrounds and experiences to make a positive impact and promote unity within Metallus and our communities. In 2024, our ERGs continued to expand their programming and employee engagement with the support of the advisory council. Metallus is also proudly involved in several organizations that promote and foster belonging and inclusion in our community and industry.

Commitment to Human Rights

At Metallus, we are committed to the protection and advancement of human rights. We recognize our responsibility for the company's culture and the impact our practices have on society as a whole. Being ethical and responsible at our core means that we believe in treating all people with dignity and respect, from our workplaces to our supply chain partners. As further detailed in our applicable policies, Metallus does not tolerate discrimination, harassment or disrespect of an individual for any reason, and we strictly forbid any form of child labor, forced labor or slavery, or human trafficking at any of our facilities or within our supply chain. Metallus' published supplier code of conduct outlines our expectations for suppliers in the areas of human rights, ethical business practices, responsible sourcing, environmental sustainability and information security. Our supplier code of conduct, along with standalone policies on human rights, child and forced labor, conflict minerals and human trafficking, can be found on the Sustainability page of our website at www.metallus.com. These policies, together with our Code of Conduct, include additional details regarding our commitment to human rights.

More information on Metallus' corporate responsibility can be found on the Sustainability page of our website at www.metallus.com.

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periodically reviews the Board's leadership structure and its appropriateness given the needs of the Board and the company at such time. In addition, the Board believes its risk oversight framework, as described under "Risk oversight" and "Sustainability oversight and risk management," would be effective under a variety of leadership structures, and therefore does not materially affect its choice of structure.

In addition to our independent non-executivechairman, independent directors chair the Board's three standing committees: the Audit Committee, chaired by Donald T. Misheff; the Compensation Committee, chaired by Kenneth V. Garcia; and the Nominating and Corporate Governance Committee, chaired by Randall A. Wotring. In their capacities as independent committee chairs, Messrs. Garcia, Misheff and Wotring each have responsibilities that contribute to the Board's oversight of management, as well as facilitating communication among the Board and management.

Annual board and committee evaluations

The Board, through the Nominating and Corporate Governance Committee, conducts an annual self-evaluation to assess the effectiveness and performance of the Board. Each committee also conducts an annual self-evaluation to assess the effectiveness and performance of the committee.

The Nominating and Corporate Governance Committee designs and establishes the overall evaluation framework. The chairperson of the Nominating and Corporate Governance Committee leads the evaluation interviews and feedback for the Board and the Nominating and Corporate Governance Committee, while the chairpersons of the Audit Committee and Compensation Committee lead the interviews and feedback for their respective committees. One-on-onediscussions are conducted with each director to obtain their assessment of the effectiveness and performance of the Board and each committee on which the director serves. The substance of the discussion is at the absolute discretion of the participants, but the Nominating and Corporate Governance Committee may provide an outline of topics in order to help focus the discussion. Discussion topics may include, among other matters, Board and committee composition and refreshment, including the process for identifying and evaluating potential candidates and whether the Board and committees have the appropriate mix of experience, skills and expertise; committee structure; peer reviews; conduct of Board and committee meetings, including timing, location, content and materials; identification of areas for increased or decreased focus by the Board and committees; and access to appropriate resources.

For the Board evaluation, a summary of the results is presented to the Board on an anonymous basis, identifying any themes or issues that have emerged. Similarly, each committee reviews a summary of the results of its evaluation and reports the results to the Board. In response to feedback received during the board and committee evaluation process for 2024, actions are being taken to provide additional information on specified areas of focus, including succession planning.

Director tenure

As discussed in more detail under "Proposal 1 - Election of Directors," pursuant to the majority voting policy of the Board of Directors, any director who receives a greater number of "withhold" votes than votes "for" his or her election in an uncontested election will submit his or her resignation to the Board of Directors promptly after the certification of the election results, which the Board of Directors may determine to reject. In addition, any director who experiences a change in primary occupation, position or business affiliation, including retirement, is required to tender a resignation to the Chairman, conditional upon acceptance by the Board of Directors. The Board may decline to accept any such resignation. In addition, the Board has implemented a policy that requires directors to retire from the Board of Directors at the first annual meeting of shareholders after reaching the age of 75, unless the Board approves an exception to this policy. The Board has not established director term limits, as longer tenured directors can provide valuable insight into the Company and its operations. The Nominating and Corporate Governance Committee evaluates the qualifications and contributions of each incumbent director before recommending the nomination of such director for an additional term.

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Director overboarding policy

Pursuant to our Corporate Governance Guidelines, directors may not serve on more than three other public company boards in addition to our Board of Directors. Any director who is also our Chief Executive Officer or other named executive officer may not serve on more than one additional public company board. The Board may approve exceptions to these limits. All of our current directors comply with our overboarding policy.

In addition to the numerical overboarding limits described above, the Corporate Governance Guidelines provide that Board members are expected to devote the time necessary to discharge their responsibilities appropriately.

Risk oversight

The Board of Directors, in close coordination with its standing committees, oversees the company's management of risk, including operational, financial, legal, regulatory, human capital, data security, cybersecurity and information technology, environmental and strategic risks, as well as the company's processes for identifying, reporting and mitigating risks. In recent years, management and the Board have also discussed risks relating to trade policies, supply chain disruption and inflation as a result of the global economic environment, as well as risks related to artificial intelligence.

Each year, management, under the leadership of the Senior Director - Internal Audit, conducts an enterprise risk management ("ERM") assessment and presents its findings to the Board of Directors, including the identification of top risks to the organization. Throughout the year, management reviews these risks and discusses new events or emerging trends (engaging with outside advisors where appropriate) that may change the top risks or impact the likelihood and magnitude of such risks. In addition to the enterprise risk management assessment, at least quarterly, management reviews with the Board the anticipated risks and opportunities, both internal and external, for the company's annual business plan, including an assessment of the likelihood and magnitude of each such risk and opportunity.

The Audit Committee reviews and discusses the guidelines, policies and processes by which the CEO and senior management of the company assess and manage risks and discusses the company's major financial risk exposures and the steps management has taken to monitor and control those exposures. The Compensation Committee considers potential risks arising from the company's compensation policies and practices for its employees, risk management practices and whether the company's compensation programs encourage unnecessary or excessive risk-taking, as discussed further in the Compensation Discussion and Analysis.

Where the Board of Directors, directly or through another committee of the Board, has processes in place to oversee the management and assessment of non-financialrisks, the Audit Committee will review such risk management processes in a general manner. The Board believes that this approach, supported by our senior leadership structure, provides appropriate checks and balances against undue risk-taking.

For additional information regarding oversight of sustainability risks by the Board of Directors and its committees, see "Sustainability oversight and risk management."

Cybersecurity and information security risk oversight

Our cybersecurity program is led by a team of skilled cybersecurity professionals, including dedicated internal cybersecurity resources and external advisors. In the normal course of business, we may collect and store sensitive information, including proprietary and confidential business information, trade secrets, intellectual property, sensitive third-party information and employee information. We maintain a robust cybersecurity incident response plan, which details the incident response procedures, tactical and strategic team membership, and points of contact related to the response processes. The company also maintains a detailed decision-tree-based playbook which is a supplement to the plan and focuses on specific types of

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incidents and the appropriate response steps. Cybersecurity is an important part of our ERM program, and the company seeks to address cybersecurity risks through a comprehensive, cross-functional approach. The company's cybersecurity policies, standards, processes, and practices for assessing, identifying and managing material risks from cybersecurity threats and responding to cybersecurity incidents are fully integrated into the company's ERM program. The plan and playbook are structured to align with the National Institute of Standards and Technology ("NIST") Cybersecurity framework practices. The plan and playbook are reviewed at least annually. In addition, we maintain insurance that includes cybersecurity coverage.

The company adheres to a periodic, third-party facilitated testing exercise of the cybersecurity incident response plan and playbook with the company's tactical and strategic team members. The teams are comprised of key members of the organization and external advisors who hold critical importance in the handling of cybersecurity events. The exercise covers response procedures for prevalent cybersecurity incidents including but not limited to phishing, third-party breaches, and a standard incident response process. The documentation helps leaders make appropriate, pre-planneddecisions. To assist, appendices detailing generalized incident response checklists and workflows from the Cybersecurity & Infrastructure Security Agency and the NIST are referenced and used as a framework. Lastly, the response plans contain instructions on collecting and incorporating lessons learned after a successful identification and remediation of a security event. The information security team also works in partnership with the company's internal audit team to review information technology-related internal controls with our external auditor as part of our overall internal controls process.

In addition, the rapid evolution and increased adoption of artificial intelligence ("AI") and similar machine learning technologies may intensify our cybersecurity risks. In 2024, we established an AI council comprised of a cross-functional group of employees with an objective to deliver value by providing education regarding the uses, benefits and risks of AI and similar technologies in our business, establishing a governance framework and principles for our use of AI, and enabling deliberate experimentation with new technologies employing AI. At this time, our use of AI is focused primarily on data analytics and improving product quality and asset reliability.

In light of the pervasive and increasing threat from cyberattacks, the Board of Directors, with input from management, assesses the measures implemented by us to mitigate and prevent cyberattacks. The company's information technology leadership team consults with and provides regular updates to the Board of Directors, as well as our chief executive officer and other members of our senior management team, as appropriate, on technology and cybersecurity matters, the status of projects to strengthen our information security systems, assessments of the information security program, timely reports regarding any cybersecurity incident that meets established reporting thresholds, and the emerging threat landscape. The information technology leadership team also consults regularly with the Board of Director's cybersecurity expert in between meetings. Our program is evaluated by internal and external experts with the results of those reviews reported to senior management and the Board of Directors at least semi-annually.

In addition, the company has an information technology governance committee, which is comprised of the chief executive officer, the other executive officers and the information technology leadership team. The information technology governance committee meets at least quarterly and as necessary to discuss the cybersecurity program and other relevant topics.

In an effort to enhance the skills and capabilities of the Board of Directors and improve the Board's oversight of cybersecurity risks, in 2022 the Board appointed Mary Ellen Baker as a director. Ms. Baker brings to the Board additional technology and cybersecurity expertise, with extensive experience in governance and risk oversight related to technology, cybersecurity and control environment assurance, as well as large-scale technology, operations, cybersecurity and enterprise data initiatives. The Board of Directors has oversight responsibility for our data security practices and we believe the Board has the requisite skills and awareness into the design and operation of our data security practices to fulfill this responsibility effectively.

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Related-party transactions approval policy

As noted, our directors and employees, including our executive officers, are subject to the Metallus Inc. Code of Conduct, which requires employees and directors to act in the best interests of the company and to avoid actual or potential conflicts of interest. To fulfill this duty, employees and directors must avoid situations in which their actions or loyalties are, or may appear to be, divided. While not every situation can be identified in a written policy, our Code of Conduct specifically prohibits the following situations:

Pursuant to the Code of Conduct, employees' requests for waivers of the Code of Conduct, including but not limited to waivers of any potential or actual conflict of interest, must be submitted to and approved by the General Counsel. Any requested waivers of the Code of Conduct for directors or executive officers can be made only by the Board of Directors or the Nominating and Corporate Governance Committee of the Board. Any such waivers for directors or executive officers will be disclosed promptly in accordance with applicable law and the rules of the New York Stock Exchange. We intend to disclose any such waiver, or any amendment to our Code of Conduct, within four business days on our website at www.metallus.com. There were no requests for, or grants of, waivers of the Code of Conduct for any of our executive officers or directors in 2024.

The Nominating and Corporate Governance Committee also is responsible for reviewing and, if appropriate, approving or ratifying any related-party transaction required to be disclosed under Item 404(a) of Regulation S-Kof the Securities Act of 1933. In this regard, during 2024, the company purchased approximately $5.2M in products from, and sold approximately $14.1M in products to, various companies affiliated with Ellwood Group, Inc. ("Ellwood"). As of February 28, 2025 and throughout 2024, Ellwood owned more than 5 percent of the company's outstanding common shares and therefore constituted a "related party" for purposes of Item 404(a). The purchases and sales between the company and affiliates of Ellwood were made in the ordinary course of business and on an arms-length basis and have been approved by the Nominating and Corporate Governance Committee.

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Beneficial ownership of common stock

Directors and officers ownership

The following table shows, as of February 28, 2025, the beneficial ownership of our common shares by each director, nominee for director and NEO, and by all directors, nominees for director and current executive officers as a group.

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Five percent shareholders

The following table provides information known to us about each beneficial owner of more than 5 percent of our common shares as of February 28, 2025, unless otherwise indicated below.

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Proposal 2

Ratification of selection of

independent auditor

Appointment of independent auditor for 2025

The Audit Committee of the Board of Directors has selected Ernst & Young LLP, an independent registered public accounting firm, to perform the audit of the company's financial statements and our internal control over financial reporting for the 2025 fiscal year. Ernst & Young has served as Metallus' independent auditor since 2012.

The selection of Ernst & Young as our independent auditor is not required to be submitted to a vote of our shareholders for ratification, but our Board of Directors believes obtaining shareholder ratification is a sound governance practice. If our shareholders fail to vote in favor of the selection of Ernst & Young, the Audit Committee will reconsider whether to retain Ernst & Young and may retain that firm or another firm without resubmitting the matter to our shareholders. Even if the shareholders ratify this appointment, the Audit Committee may, in its discretion, direct the appointment of a different independent registered public accounting firm at any time during the year if it determines that such a change would be in the company's best interest.

Representatives of Ernst & Young are expected to be present at the 2025 annual meeting of shareholders. They will have an opportunity to make a statement if they desire to do so and will be available to respond to appropriate questions.

Ratification of the appointment of Ernst & Young as the company's independent auditor for the 2025 fiscal year requires the affirmative vote of a majority of the votes cast on the proposal.

Shares represented by proxy will be voted FOR this proposal unless you specify otherwise in your voting instructions.

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Services of independent auditor for 2024

Set forth below are the aggregate fees billed by Ernst & Young for professional services rendered to the company for the fiscal years ended December 31, 2023 and 2024:

Audit Committee pre-approvalpolicies and procedures

The Audit Committee annually approves the scope of services and fees payable for the year-endaudit and statutory audits to be performed by the independent auditor for the next fiscal year. In addition, the Audit Committee has adopted a pre-approvalpolicy pursuant to which the Committee annually approves certain audit, audit-related and tax services that may be provided by the independent auditor, along with the associated fees for such services, during the upcoming fiscal year. Other than services pre-approvedin connection with the annual engagement of the independent auditor or pursuant to the pre-approvalpolicy, all services to be provided by the independent auditor must be specifically pre-approvedby the Audit Committee. Requests for pre-approvalmust contain sufficient detail to ensure the Audit Committee knows precisely what services it is being asked to pre-approveso that it can make a well-reasoned assessment of the impact of the service on the auditor's independence. With certain specified limitations, the Audit Committee has delegated its pre-approvalauthority to its chairperson, who must report any pre-approvaldecisions to the full Audit Committee at its next scheduled meeting. All of the services described above were approved by the Audit Committee in accordance with the foregoing policies and procedures.

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Proposal 3

Approval, on an advisory basis, of named executive officer compensation

We are asking our shareholders to approve, on an advisory basis, the compensation of our named executive officers as disclosed in this proxy statement. Although this is an advisory vote, and therefore not binding on our Board of Directors, the Compensation Committee, which is responsible for designing and administering our executive compensation program, values the opinions expressed by our shareholders with respect to this proposal and will review and consider the voting results when making future decisions regarding our executive compensation programs. While we aim to continuously improve our pay practices, we are pleased with the positive feedback from our shareholders and their strong historical endorsement of our executive compensation program, which is reflected in an average of approximately 98% of votes cast in favor of our "say-on-pay"proposal over the past three years. At the 2024 annual meeting of shareholders, the "say-on-pay"advisory vote passed with approximately 99% of votes cast in favor of our proposal.

We conduct this "say-on-pay"vote annually as we consider it to be a matter of good corporate governance. We anticipate that shareholders will next have the opportunity to vote on the frequency of future advisory votes on the compensation of our named executive officers at the 2027 annual meeting of shareholders.

As we explain in the compensation discussion and analysis that follows, our executive compensation program is designed to attract, retain, motivate and reward our named executive officers for achieving specific annual, long-term and strategic goals, and also for increasing shareholder value. We believe the compensation program for our named executive officers:

We encourage you to review carefully the compensation discussion and analysis, the compensation tables and related disclosures included in this proxy statement. They contain information about the processes the Compensation Committee follows and the factors it considers when determining compensation for our named executive officers. They also describe the primary elements of our executive compensation program and the 2024 compensation of our named executive officers.

Therefore, as required under the Dodd-Frank Wall Street Reform and Consumer Protection Act and Section 14A of the Exchange Act, we are asking you to approve, on an advisory (non-binding)basis, the following resolution at our 2025 annual meeting of shareholders:

RESOLVED, that the compensation of the named executive officers as disclosed pursuant to the compensation disclosure rules of the Securities and Exchange Commission, including the compensation discussion and analysis, the compensation tables and other related material disclosed in this proxy statement, is hereby APPROVED.

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The Board recommends that shareholders indicate their support for the compensation of the company's named executive officers as described in this proxy statement by voting "FOR" approval of this proposal at the annual meeting. The Compensation Committee will consider the affirmative vote of a majority of the votes cast on this proposal as approval of the compensation paid to the company's named executive officers. If there are a significant number of negative votes, the Compensation Committee will seek to understand and consider the concerns that influenced such votes in making future decisions about executive compensation programs.

Shares represented by proxy will be voted FOR this proposal unless you specify otherwise in your voting instructions.

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Compensation discussion and analysis

This Compensation Discussion and Analysis ("CD&A") provides an overview of our named executive officer ("NEO") compensation philosophy and practices, and the factors considered by the Compensation Committee in granting and delivering NEO compensation for 2024.

This CD&A focuses on the following individuals, whom we have determined to be the company's NEOs for 2024:

Executive summary

Our 2024 business performance

In 2024, weak market demand across many of our end markets drove lower ship tons and utilization rates, resulting in financial results well below expectations. Over the past few years and with a focus on continuous improvement, we have structurally enhanced our business to be more resilient against economic downturns such as those experienced in 2024. As a result, despite challenging market conditions, we delivered positive net income and operating cash flow in 2024 while maintaining a strong balance sheet and returning capital to shareholders through our share repurchase program.

Throughout the year, our team remained focused on maintaining and investing in our world-class assets aimed at improving safety, quality and efficiency. In addition, we continued to provide training and development opportunities for our employees. We believe these actions are not only critical for our long-term growth but will help us emerge from the current downtustronger and ready to capitalize on opportunities as market conditions improve.

In 2024, Metallus entered into an agreement with the U.S. Army for $99.75 million in funding to support their mission of increasing munitions production for national security in the upcoming years, as well as an agreement for $3.5 million in grants from JobsOhio. The funding agreements support the commissioning of two major assets: a continuous bloom reheat furnace and a roller hearth heat treat furnace. These assets are expected to enhance production capacity, improve processing efficiencies, increase first-time quality and reduce yield loss, benefiting all our customers.

As we conduct our business, we continue to consistently prioritize safety which remains a core value at Metallus. In 2024, we spent approximately $8 million on safety equipment and comprehensive training programs company-wide. Our goal is to ensure that our employees end each day injury and incident free. As a reminder, a significant portion of the annual incentive for each leader in our organization is tied directly to achieving specific safety targets.

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In 2024, our teams made significant strides not only in safety but in other areas that we believe will drive long-term shareholder value, including:

We remain committed to delivering value to our shareholders, as demonstrated by our capital allocation strategy, which includes strategic reinvestment in our business and our ongoing share repurchase program. In 2024, the company invested $64.8 million in capital expenditures and deployed $54.8 million for shareholder retuactivities, further reducing diluted shares outstanding.

Pay for performance

At Metallus, we believe in rewarding employees, including our NEOs, for helping the company achieve our corporate goals, deliver exceptional performance and build shareholder value. In this spirit, we designed our executive compensation program to further the following objectives:

The compensation of our NEOs during 2024 reflects our financial results both for the current year and the three-year period ended December 31, 2024, and demonstrates that our compensation plans pay for performance as intended. For example:

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2024 say-on-payvote and 2025 executive compensation changes

In 2024, shareholders approved the compensation of our NEOs with approximately 99 percent of votes cast in favor of our "say-on-pay"proposal. Our Compensation Committee considered the strong results of this advisory vote, plus the changes made to executive compensation programs in recent years, recent shareholder feedback and market data in its annual review of our executive compensation plans. Based on this review and evaluation, for 2025, the Compensation Committee has determined to continue to focus the annual incentive plan on profitability, cash flow generation and safety, and to continue to use relative total shareholder return, measured for the one-,two-and three-year periods within a three-year performance cycle, as the metric for the performance shares awarded under the company's long term incentive plan.

With respect to the long-term incentive plan's annual awards, the Committee has determined that all regular long-term incentive grants made in 2025 will continue to be in the form of performance shares and time-based restricted stock units, with the long-term incentive mix for Mr. Williams remaining approximately 60 percent performance shares and 40 percent time-based restricted stock units, and the long-term

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incentive mix for the other NEOs remaining approximately 50 percent performance shares and 50 percent time-based restricted stock units.

Finally, in connection with the annual review of the compensation of the company's President and CEO, in February 2025 the Compensation Committee recommended and the Board approved for Mr. Williams an increase in (i) annual base salary from $875,000 to $910,000, (ii) the target annual incentive opportunity (as a percentage of base salary) from 100 percent to 110 percent and (iii) the target value of awards under the company's long-term incentive plan from $3.25 million to $3.35 million annually. The Compensation Committee's recommendation was based primarily on a finding that the current target total direct compensation for Mr. Williams fell below the market median (as compared to peer group compensation data provided by Meridian, the Committee's independent compensation consultant).

Executive compensation highlights

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Our compensation philosophy

At Metallus, our executive compensation program is designed to align our executives' interests with those of our shareholders, to reward leaders for strong business results and to attract, retain and motivate the best talent in the industry.

Our executive compensation philosophy embodies the following principles: