Exhibit 32.1

CERTIFICATION PURSUANT TO
18 U.S.C. 1350
AS ADOPTED PURSUANT TO
SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

     In connection with the Quarterly Report on Form 10-Q of Horsehead Holding Corp. (the “Company”) for the quarter ended June 30, 2010, as filed with the Securities and Exchange Commission on the date hereof (the “Report”), each of the undersigned president and chief executive officer and vice president and chief financial officer of the Company, certifies, pursuant to 18 U.S.C. 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that:

     1. The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

     2. The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company.

/s/ James M. Hensler	/s/ Robert D. Scherich
James M. Hensler President and Chief Executive Officer	Robert D. Scherich Vice President and Chief Financial Officer

Date: August 9, 2010 Date: August 9, 2010

A signed original of this written statement has been provided to the Company and will be retained by the Company and furnished to the Securities and Exchange Commission or its staff upon request.