**Exhibit 4.21****AMENDMENT NO. 15 TO****AMENDED AND RESTATED CREDIT AGREEMENT**     This Amendment No. 15 to Amended and Restated Credit Agreement (this “***Amendment***”), dated as ofAugust 14, 2006, is entered into by and between **SIFCO INDUSTRIES, INC.**(the “***Borrower***”) and**NATIONAL CITY BANK**(the “***Bank***”) for the purposes amending and supplementing the documents andinstruments referred to below.WITNESSETH:     WHEREAS, Borrower and Bank are parties to an Amended and Restated Credit Agreement made as ofApril 30, 2002, as amended from time to time (as amended, the “***Credit Agreement***” providing for**$6,000,000**of revolving credits; all terms used in the Credit Agreement being used herein with thesame meaning); and     WHEREAS, Borrower and Bank desire to further amend certain provisions of the Credit Agreementto, among other things, amend and/or waive certain financial covenants applicable thereto;     NOW, THEREFORE, in consideration of the foregoing and the mutual covenants and agreementscontained herein and for other good and valuable consideration, the receipt and sufficiency ofwhich is hereby acknowledged, the parties agree as follows:**SECTION I —****Amendments to Credit Agreement** A. Subsection 2A.02 of the Credit Agreement is hereby amended to extend theExpiration Date from March 31, 2007 to October 1, 2007.  B. Subsection 3B.01 of the Credit Agreement is hereby amended in its entirety toread as follows:    3B.01 TANGIBLE NET WORTH — Borrower shall not suffer or permit the Tangible Net Worthof the Reporting Group, as of the end of any month, to be less than the required minimumamount. The required minimum amount shall be $21,500,000. The required minimum amountshall increase as of the last day of each fiscal year of Borrower, commencing withfiscal year ending September 30, 2007, by an amount equal to **50%**of the consolidated NetIncome of the Reporting Group for such fiscal year as measured by Borrower’s annualaudited financial statements for such fiscal year. If Net Income is less than $0 forany fiscal year, the required minimum amount shall not be reduced as of the end of thatfiscal year.**SECTION II —****Waiver**     Bank hereby waives all violations of section 3B.01 of the Credit Agreement, captioned TANGIBLENET WORTH, which occurred prior to May 1, 2006. The execution, delivery and effectiveness of thisAmendment and the specific waiver set forth herein shall not operate as a waiver of any otherright, power or remedy of Bank under the Credit Agreement or constitute a continuing waiver of anykind.**SECTION III —****Representations and Warranties**     Borrower hereby represents and warrants to Bank, to the best of Borrower’s knowledge, that (A) none of the representations and warranties made in the Credit Agreement or anyRelated Writing, (collectively, the “Loan Documents”) has ceased to be true andcomplete in any material respect as of the date hereof; and  (B) as of the date hereof no “Default” has occurred that is continuing under theLoan Documents.
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**SECTION IV —****Acknowledgments Concerning Outstanding Loans**     Borrower acknowledges and agrees that, as of the date hereof, all of Borrower’s outstandingloan obligations to Bank are owed without any offset, deduction, defense, claim or counterclaim ofany nature whatsoever. Borrower authorizes Bank to share all credit and financial informationrelating to Borrower with each of Bank’s parent company and with any subsidiary or affiliatecompany of such Bank or of such Bank’s parent company.**SECTION V —****References**     On and after the effective date of this Amendment, each reference in the Credit Agreement to“this Agreement”, “hereunder”, “hereof”, or words of like import referring to the Credit Agreementshall mean and refer to the Credit Agreement as amended hereby. The Loan Documents, as amended bythis Amendment, are and shall continue to be in full force and effect and are hereby ratified andconfirmed in all respects. The execution, delivery and effectiveness of this Amendment shall notoperate as a waiver of any right, power or remedy of Bank under the Loan Documents or constitute awaiver of any provision of the Loan Documents except as specifically set forth herein.**SECTION VI —****Counterparts and Governing Law**     This Amendment may be executed in any number of counterparts, each counterpart to be executedby one or more of the parties but, when taken together, all counterparts shall constitute oneagreement. This Amendment, and the respective rights and obligations of the parties hereto, shallbe construed in accordance with and governed by Ohio law.     IN WITNESS WHEREOF, Borrower and Bank have caused this Amendment to be executed by theirauthorized officers as of the date and year first above written.   **SIFCO INDUSTRIES, INC**. **NATIONAL CITY BANK**   By:/s/ Frank A. Cappello By:/s/ Christian BrownName:Frank A. Cappello Name:Christian BrownTitle:V.P. Finance and CFO Title:Vice President
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