Exhibit 99.1

TMS International Corp. Reports Fourth Quarter

and Fiscal Year 2012 Results

PITTSBURGH, PA, February 14, 2013 – TMS International Corp. (NYSE: TMS), the parent company of Tube City IMS Corporation, a leading provider of outsourced industrial services to steel mills globally, today announced results for its fourth quarter and fiscal year ended December 31, 2012.

2012 Fourth Quarter Highlights

2012 Fourth Quarter Financial Results

Revenue After Raw Materials Costs, the company’s measurement of sales performance, was $148.3 million, an increase of 7.5%, compared to $137.9 million in the fourth quarter of 2011.

Adjusted EBITDA for the fourth quarter of 2012 was $35.0 million compared to $31.7 million of Adjusted EBITDA in the fourth quarter of 2011. Income before income taxes was $10.1 million compared to $8.0 million in the fourth quarter of 2011, for an increase of 27%. Net income attributable to common stock was $6.1 million for the fourth quarter and was flat compared to the fourth quarter of 2011, due to a higher effective tax rate in 2012. Basic and diluted earnings per share were $0.15 for the fourth quarter of 2012.

The company’s Adjusted EBITDA Margin² for the fourth quarter of 2012 was 23.6% compared to 23.0% in the fourth quarter of 2011. Total Revenue for the fourth quarter was $536.8 million compared to $617.5 million in the fourth quarter of 2011.

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Discretionary Cash Flow^1,3, which the company uses to measure operating cash flow generation, was $20.6 million for the fourth quarter of 2012 compared with $18.4 million in the fourth quarter of 2011, a 12.0% increase.

2012 Full Year Financial Results

Revenue After Raw Materials Costs for the year ended December 31, 2012, increased 10.4% to $606.7 million from $549.5 million for the comparable 2011 period. Adjusted EBITDA for 2012 increased 8.4% to $145.3 million from $134.0 million for 2011. Adjusted EBITDA margin for 2012 was 24.0% compared to 24.4% for 2011.

Total revenue for the year ended December 31, 2012, was $2.5 billion, compared to $2.7 billion for 2011. For 2012, the company produced Discretionary Cash Flow of $102.6 million compared with $92.1 million in 2011, an 11.3% increase.

Raymond Kalouche, President and Chief Executive Officer of TMS International Corp., said with respect to the company’s financial results, “We are pleased that our financial results are right in the middle of our full-year public guidance, which we provided in early 2012. Our revenue and EBITDA were up year-over-year despite a very challenging environment in the industry for much of the year. We continue to focus on creating value for our customers and shareholders in all business environments and executing our global growth plan.”

Outlook

The company expects to achieve full year 2013 Adjusted EBITDA in a range of $152 million to $160 million, representing a year-over-year growth rate of 5% to 10%.

Conference Call Information

The company will hold a conference call to discuss fourth quarter 2012 results at 11 a.m. Eastern time this morning. The call will be web cast live along with a slide presentation over the Internet from the company’s Web site at www.tmsinternationalcorp.com under “Investors.” Participants should follow the instructions provided on the Web site for downloading and installing the necessary audio and visual applications. The conference call also is available by dialing 1-800-860-2442 (domestic toll free) or 1-412-858-4600 (international) and asking for the TMS International Corp. fourth quarter earnings conference call. Following the live conference call, a replay will be available beginning one hour after the call. The replay will be available on the company’s web site or by dialing 1-877-344-7529 (domestic toll free) or 1-412-317-0088 (international) and entering the replay passcode 10022570. The telephonic replay will be available until March 1, 2013.

About TMS International Corp.

TMS International Corp., through its subsidiaries, including Tube City IMS Corporation, is the largest provider of outsourced industrial services to steel mills in North America as measured by revenue and has a substantial and growing international presence. The company provides mill services at 81 customer sites in 11 countries and operates 35 brokerage offices from which it buys and sells raw materials across five continents.

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Forward Looking Statements

Certain information in this news release contains forward-looking statements with respect to the company’s financial condition, results of operations or business or its expectations or beliefs concerning future events. Such forward-looking statements include the discussions of the potential new debt refinancing, the company’s business strategies, estimates of future global steel production and other market metrics and the company’s expectations concerning future operations, margins, profitability, liquidity and capital resources. Although the company believes that such forward-looking statements are reasonable, it cannot assure you that any forward-looking statements will prove to be correct. Forward-looking statements may be preceded by, followed by or include the words “may,” “will,” “believe,” “expect,” “anticipate,” “intend,” “plan,” “estimate,” “could,” “might,” or “continue” or the negative or other variations thereof or comparable terminology. Such forward-looking statements are not guarantees of future performance and involve risks, uncertainties, estimates and assumptions that may cause the company’s actual results, performance or achievements to be materially different. Additional information relating to factors that may cause actual results to differ from the company’s forward-looking statements can be found in the company’s most recent Annual Report on Form 10-K and elsewhere in the company’s filings with the Securities and Exchange Commission. You should not place undue reliance on any of these forward- looking statements. Any forward-looking statement speaks only as of the date on which it is made, and we undertake no obligation to update any such statement to reflect new information, or the occurrence of future events or changes in circumstances.

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TMS INTERNATIONAL CORP. AND SUBSIDIARIES

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS

(In thousands of dollars, except share and per share data)

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TMS INTERNATIONAL CORP. AND SUBSIDIARIES

CONDENSED CONSOLIDATED BALANCE SHEETS

(In thousands of dollars, except share data)

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TMS INTERNATIONAL CORP. AND SUBSIDIARIES

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS

(In thousands of dollars, except share and per share data)

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DESCRIPTION AND GAAP RECONCILIATIONS OF

CERTAIN FINANCIAL MEASUREMENTS

Revenue After Raw Materials Costs

We measure our sales volume on the basis of Revenue After Raw Materials Costs, which we define as Total Revenue minus Cost of Raw Materials Shipments. Revenue After Raw Materials Costs is not a recognized financial measure under GAAP, but we believe it is useful in measuring our operating performance because it excludes the fluctuations in the market prices of the raw materials we procure for and sell to our customers. We subtract the Cost of Raw Materials Shipments from Total Revenue because market prices of the raw materials we procure for and generally concurrently sell to our customers are offset on our statement of operations. Further, in our raw materials procurement business, we generally engage in two alternative types of transactions that require different accounting treatments for Total Revenue. In the first type, we take no title to the materials being procured and we record only our commission as revenue; in the second type, we take title to the materials and sell it to a buyer, typically in a transaction where a buyer and seller are matched. By subtracting the Cost of Raw Materials Shipments, we isolate the margin that we make on our raw materials procurement and logistics services, and we are better able to evaluate our operating performance in terms of the volume of raw materials we procure for our customers and the margin we generate.

Adjusted EBITDA

Adjusted EBITDA is not a recognized financial measure under GAAP, but we believe it is useful in measuring our operating performance. Adjusted EBITDA is used internally to determine our incentive compensation levels, including under our management bonus plan, and it is required, with some additional adjustments, in certain covenant compliance calculations under our senior secured credit facilities. We also use Adjusted EBITDA to benchmark the performance of our business against expected results, to analyze year-over-year trends and to

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compare our operating performance to that of our competitors. We also use Adjusted EBITDA as a performance measure because it excludes the impact of tax provisions and Depreciation and Amortization, which are difficult to compare across periods due to the impact of accounting for business combinations and the impact of tax net operating losses on cash taxes paid. In addition, we use Adjusted EBITDA as a performance measure of our operating segments in accordance with ASC Topic 280, Disclosures About Segments of an Enterprise and Related Information. We believe that the presentation of Adjusted EBITDA enhances our investors’ overall understanding of the financial performance of and prospects for our business.

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Discretionary Cash Flow is calculated as our Adjusted EBITDA minus our Maintenance Capital Expenditures. We believe Discretionary Cash Flow is useful in measuring our liquidity. Discretionary Cash Flow is not a recognized financial measure under GAAP, and may not be comparable to similarly titled measures used by other companies in our industry. Discretionary Cash Flow should not be considered in isolation from or as an alternative to any other performance measures determined in accordance with GAAP (in thousands):

The following table reconciles Discretionary Cash Flow to net cash provided by (used in) operating activities (in thousands):

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