UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

Form 10-K/A
Amendment No. 1

Commission file number: 1-6948

SPX Corporation
(Exact Name of Registrant as Specified in Its Charter)

13320 Ballantyne Corporate Place
Charlotte, NC 28277
(Address of Principal Executive Offices) (Zip Code)

Registrant's telephone number, including area code: 704-752-4400

Securities registered pursuant to Section 12(b) of the Act:

Securities registered pursuant to Section 12(g) of the Act:

None
(Title of Class)

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

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

        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 requirement for the past 90 days. Yes ý    No o

        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 ý    No o

        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. ý

        Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. See the definitions of "large accelerated filer," "accelerated filer," and "smaller reporting company" in Rule 12b-2 of the Exchange Act. (Check one):

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

        The aggregate market value of the voting stock held by non-affiliates of the registrant as of June 29, 2012 was $3,235,230,700. The determination of affiliate status for purposes of the foregoing calculation is not necessarily a conclusive determination for other purposes.

        The number of shares outstanding of the registrant's common stock as of February 15, 2013 was 46,985,608.

EXPLANATORY NOTE

        The sole purpose of this Amendment No. 1 on Form 10-K/A (the "Form 10-K/A") to our Annual Report on Form 10-K for the year ended December 31, 2012, originally filed with the Securities and Exchange Commission on February 22, 2013 (the "Form 10-K"), is to revise the Independent Auditors' Report included in Exhibit 99.1 to provide (i) the conformed signature of KPMG LLP and (ii) the city and state of the office of KPMG LLP that performed the audits of EGS Electrical Group LLC and Subsidiaries for the years ended September 30, 2012, 2011 and 2010. The signature and missing information had been provided by KPMG LLP, but the conformed signature line and missing information was inadvertently omitted from their Independent Auditors' Report when the Form 10-K was filed.

        This Form 10-K/A has not been updated for events occurring after the filing of the Form 10-K, and no attempt has been made in this Form 10-K/A to modify or update other disclosures as presented in the original filing of our Form 10-K.

P A R T    I V

ITEM 15. Exhibits And Financial Statement Schedules

        The following documents are filed as part of the report:

1.

All financial statements. See Index to Consolidated Financial Statements on page 47 of the Form 10-K.



2.

Financial Statement Schedules. None required. See page 47 of the Form 10-K.



3.

Exhibits. See Index to Exhibits in the Form 10-K and this Form 10-K/A.

SIGNATURES

        Pursuant to the requirements of Section 13 or 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 on this 25th day of February, 2013.

INDEX TO EXHIBITS

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