QuickLinks
 -- Click here to rapidly navigate through this document
  



 
 

Exhibit 4.6    
    


 
  Execution Copy    
    


FIRST SUPPLEMENTAL INDENTURE  


        This FIRST SUPPLEMENTAL INDENTURE, dated as of November 18, 2004, between K&F Industries, Inc. (the "Successor Company"), a permitted successor to
K&F Acquisition, Inc., a Delaware corporation (the "Company") and U.S. Bank National Association, as Trustee. 


W I T N E S S E T H  


        WHEREAS, the Company and the Trustee entered into an Indenture (the "Indenture"), dated as of November 18, 2004, pursuant to which the Company has issued
$315,000,000 in principal amount of 73/4% Senior Subordinated Notes due 2014 (the "Notes"); 


        WHEREAS,
Section 9.01(3) of the Indenture provides that the Company, the Guarantors and the Trustee may amend or supplement the Indenture in order to provide for the assumption of
the Company's obligations to Holders of Notes in the case of a merger or consolidation or sale of all or substantially all of the Company's assets, without the consent of the Holders of the Notes; and 


        WHEREAS,
all acts and things prescribed by the Indenture, by law and by the Certificate of Incorporation and the Bylaws (or comparable constituent documents) of the Successor Company and
the Trustee necessary to make this First Supplemental Indenture a valid instrument legally binding on
the Successor Company and the Trustee, in accordance with its terms, have been duly done and performed; 



        NOW
THEREFORE, to comply with the provisions of the Indenture, and in consideration of the foregoing, the Successor Company and the Trustee mutually covenant and agree for the equal and
ratable benefit of the Holders of the Notes as follows: 


ARTICLE 1  


        Section 1.01. This First Supplemental Indenture is supplemental to the Indenture and does and shall be deemed to form a part of, and shall be
construed in connection with and as part of, the Indenture for any and all purposes. 



        Section 1.02.
This First Supplemental Indenture shall become effective immediately upon its execution and delivery by each of the Company and the Trustee. 


ARTICLE 2  


        Section 2.01. In accordance with Section 5.02 of the Indenture, the Successor Company hereby agrees to be bound by the terms, conditions and other
provisions of, and assumes all of the obligations under, the Indenture and the Notes with all attendant rights, duties and obligations stated therein, on a joint and several basis with the parties
hereto and thereto, with the same force and effect as if originally named as the Company therein and as if such party executed the Indenture on the date thereof. The Successor Company represents and
warrants that all of the conditions set forth in Section 5.01 of the Indenture are satisfied. 


ARTICLE 3  


        Section 3.01. Except as specifically modified herein, the Indenture and the Notes are in all respects ratified and confirmed (mutatis mutandis) and shall
remain in full force and effect in accordance with their terms. 


1







 



        Section 3.02.
All capitalized terms used but not defined herein shall have the same respective meanings ascribed to them in the Indenture. 


        Section 3.03.
Except as otherwise expressly provided herein, no duties, responsibilities or liabilities are assumed, or shall be construed to be assumed, by the Trustee by reason
of this First Supplemental Indenture. This First Supplemental Indenture is executed and accepted by the Trustee subject to all of the terms and conditions set forth in the Indenture with the same
force and effect as if those terms and conditions were repeated at length herein and made applicable to the Trustee with respect hereto. 


        Section 3.04.
THIS FIRST SUPPLEMENTAL INDENTURE SHALL BE GOVERNED BY, AND CONSTRUED IN ACCORDANCE WITH, THE LAWS OF THE STATE OF NEW YORK. 


        Section 3.05.
The parties may sign any number of copies of this First Supplemental Indenture. Each signed copy shall be an original, but all of them together represent the same
agreement. 


        Section 3.06.
The headings herein are inserted for convenience of reference only and are not intended to be part of, or to affect the meaning or interpretation of, this letter
agreement. 


        Section 3.07.
The recitals hereto are statements only of the Company and shall not be considered statements of or attributable to the Trustee. 


[Signature Page to Follow]


2







 

        IN
WITNESS WHEREOF, the parties hereto have caused this First Supplemental Indenture to be duly executed and attested, all as of the date first above written. 



	 	 	K&F INDUSTRIES, INC.
	

 	
 	

By:	

/s/  KENNETH M. SCHWARTZ      
 Name: Kenneth M. Schwartz

Title: President	
 	

 
	 	 	 	 	 	 
	

 	
 	

U.S. BANK NATIONAL ASSOCIATION, as Trustee
	

 	
 	

By:	

/s/  CAUNA M. SILVA      
 Name: Cauna M. Silva

Title: Vice President	
 	

 
	 	 	 	 	 	 




3











QuickLinks



Exhibit 4.6

Execution Copy