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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-K/A

(Amendment No. 1)

(Mark One)

For the fiscal year ended December 31, 2011

For the transition period from                  to                 

Commission File Number 333-150749

AGY HOLDING CORP.

(Exact name of registrant as specified in its charter)

2556 Wagener Road

Aiken, South Carolina 29801

(Address of Principal Executive Offices) (Zip Code)

Registrant’s telephone number, including area code: (888) 434-0945

Securities registered pursuant to Section 12(b) of the Act: NONE

Securities registered pursuant to Section 12(g) of the Act: NONE

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act.    Yes  ¨    No  x

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Exchange Act.    Yes  x    No  ¨

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.    Yes  x    No  ¨

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§ 232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files).    Yes  x    No  ¨

Indicate by check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K is not contained herein, and will not be contained, to the best of registrant’s knowledge, in definitive proxy or information statements incorporated by reference in Part III of this Form 10-K or any amendment to this Form 10-K.    x

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, or a non-accelerated filer. See definition of “accelerated filer and large accelerated filer” in Rule 12b-2 of the Exchange Act.

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).    Yes  ¨    No  x

The registrant is privately held. There is no trading in its common equity, and therefore an aggregate market value of common stock of the registrant based on sales or bid and asked prices is not determinable.

The total number of shares of the registrant’s common stock, par value $0.01 per share, outstanding as of March 30, 2012 was 100.

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AGY HOLDING CORP.

INDEX

EXPLANATORY NOTE

This Amendment No. 1 on Form 10-K/A (this “Amendment”) amends the Annual Report on Form 10-K of AGY Holding Corp., a Delaware corporation (the “Company”) for the fiscal year ended December 31, 2011, originally filed with the Securities and Exchange Commission on March 30, 2012 (the “Original Filing”). This Amendment is being filed as an exhibit-only filing solely to furnish amended certifications by the Company’s principal executive officer and principal financial officer, which are amended to include the full text in Exhibits 31.1 and 31.2 in accordance with Item 601(b)(31) of Regulation S-K.

This Amendment should be read in conjunction with the Original Filing. Except as described above, no attempt has been made in this Amendment to modify or update any other items or disclosures presented in the Original Filing. This Amendment does not reflect events occurring after the date of the Original Filing or modify or update those disclosures that may be affected by subsequent events.

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PART IV

The financial statements are filed as part of the Annual Report on Form 10-K under Item 8 – “Financial Statements.”

Financial statement schedules have been omitted because they are either not required, not applicable, or the information is presented in the Consolidated Financial Statements and the notes thereto in Item 8 of the Form 10-K.

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SIGNATURES

Pursuant to the requirements of Section 13 or Section 15(d) of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized in the City of Aiken, State of South Carolina, on the 14^th day of September, 2012.