EX-4.1



 Exhibit 4.1 

AK Steel Corporation 
 as
the Company 
 AK Steel Holding Corporation 

as the Parent Guarantor 

AK Tube LLC, AK Steel Properties, Inc. and Mountain State Carbon, LLC, 

As Subsidiary Guarantors 

and 
 U.S. Bank National
Association, 
 as Trustee 

Seventh Supplemental Indenture 

Dated as of March 23, 2017 







 TABLE OF CONTENTS 

 
  

 

							
	 	  	 	  	PAGE	 
	ARTICLE 1	 
	SCOPE OF SEVENTH SUPPLEMENTAL INDENTURE	 
			
	 Section 1.01.
	  	 Scope
	  	 	2	 
	
	ARTICLE 2	 
	DEFINITIONS	 
			
	 Section 2.01.
	  	 Definitions and Other Provisions of General Application
	  	 	2	 
	 Section 2.02.
	  	 Other Definitions
	  	 	10	 
	
	ARTICLE 3	 
	FORM AND TERMS OF THE NOTES	 
			
	 Section 3.01.
	  	 Form and Dating
	  	 	10	 
	 Section 3.02.
	  	 Terms of the Notes
	  	 	10	 
	
	 ARTICLE 4
	  

	CHANGE OF CONTROL	 
			
	 Section 4.01.
	  	 Redemption Upon Change of Control
	  	 	12	 
	
	 ARTICLE 5
	  

	COVENANTS	 
			
	 Section 5.01.
	  	 Limitation On Liens
	  	 	14	 
	 Section 5.02.
	  	 Limitation On Subsidiary Debt
	  	 	16	 
	 Section 5.03.
	  	 Limitation on Sale and Leaseback
	  	 	18	 
	
	 ARTICLE 6
	  

	CONSOLIDATION, MERGER OR SALE OF ASSETS	 
			
	 Section 6.01.
	  	 In General
	  	 	19	 
	 Section 6.02.
	  	 Additional Provisions
	  	 	19	 
	
	 ARTICLE 7
	  

	DEFAULT AND REMEDIES	 
			
	 Section 7.01.
	  	 In General
	  	 	19	 
	 Section 7.02.
	  	 Additional Provisions
	  	 	19	 


  
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	ARTICLE 8	 
	SATISFACTION AND DISCHARGE; DEFEASANCE	 
			
	 Section 8.01.
	  	 In General
	  	 	19	 
	 Section 8.02.
	  	 Satisfaction and Discharge of Indenture
	  	 	20	 
	 Section 8.03.
	  	 Legal Defeasance and Discharge
	  	 	20	 
	 Section 8.04.
	  	 Defeasance of Certain Obligations
	  	 	21	 
	
	 ARTICLE 9
	  

	AMENDMENTS, SUPPLEMENTS AND WAIVERS	 
			
	 Section 9.01.
	  	 In General
	  	 	22	 
	 Section 9.02.
	  	 Amendments Without Consent of Holders
	  	 	22	 
	 Section 9.03.
	  	 Amendments with Consent of Holders
	  	 	22	 
	
	 ARTICLE 10
	  

	GUARANTEES	 
			
	 Section 10.01.
	  	 In General
	  	 	22	 
	 Section 10.02.
	  	 Additional Provisions
	  	 	23	 
	
	 ARTICLE 11
	  

	MISCELLANEOUS	 
			
	 Section 11.01.
	  	 Trust Indenture Act of 1939
	  	 	25	 
	 Section 11.02.
	  	 Governing Law
	  	 	25	 
	 Section 11.03.
	  	 Duplicate Originals
	  	 	25	 
	 Section 11.04.
	  	 Separability
	  	 	25	 
	 Section 11.05.
	  	 Ratification
	  	 	26	 
	 Section 11.06.
	  	 Effectiveness
	  	 	26	 
	 Section 11.07.
	  	 Successors
	  	 	26	 
	 Section 11.08.
	  	 Trustee’s Disclaimer
	  	 	26	 
			
	 EXHIBIT A
	  		  	 	A-1	 
	 EXHIBIT B
	  		  	 	B-1	 


  
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 SEVENTH SUPPLEMENTAL INDENTURE 

SEVENTH SUPPLEMENTAL INDENTURE (this “Seventh Supplemental Indenture”), dated as of March 23, 2017, between AK Steel
Corporation, a Delaware corporation (the “Company”), AK Steel Holding Corporation, a Delaware corporation, as Parent Guarantor, AK Tube LLC, a Delaware limited liability company (“AK Tube”), AK Steel Properties,
Inc., a Delaware Corporation (“AK Steel Properties”), and Mountain State Carbon, LLC, a Delaware limited liability company (“MSC,” and together with AK Tube and AK Steel Properties, each a “Subsidiary
Guarantor” or “Guaranteeing Subsidiary” and together the “Guaranteeing Subsidiaries” or “Subsidiary Guarantors”), as guarantors, and U.S. Bank National Association, a national banking
association, as trustee (the “Trustee”). 
 RECITALS OF THE COMPANY 

WHEREAS, the Company, the Parent Guarantor and the Trustee executed and delivered an Indenture, dated as of May 11, 2010 (the
“Base Indenture” and as supplemented by the Fourth Supplemental Indenture, dated as of April 29, 2014 (the “Fourth Supplemental Indenture”), among the Company, the Parent Guarantor, AK Tube, AK Steel Properties
and the Trustee, the Sixth Supplemental Indenture, dated as of July 27, 2016 (the “Sixth Supplemental Indenture”), among the Company, the Parent Guarantor, MSC and the Trustee, and this Seventh Supplemental Indenture, the
“Indenture”), to provide for the issuance by the Company from time to time of its senior debentures, notes or other evidences of indebtedness (the “Securities”); 

WHEREAS, Sections 2.01, 2.03 and 11.01 of the Base Indenture provide that the Company and the Parent Guarantor, when authorized by a Board
Resolution, and the Trustee, at any time and from time to time, may enter into one or more indentures supplemental to the Indenture, without the consent of any Holders, to, among other things, establish the form or terms of Securities of any series
as permitted by the Indenture; 
 WHEREAS, the issuance and sale of $400,000,000 aggregate principal amount of a new series of the
Securities of the Company designated as its 7.00% Senior Notes due 2027 (the “Notes”) have been authorized by resolutions adopted by the board of directors of each of the Company, the Parent Guarantor and the Subsidiary Guarantors;

 WHEREAS, the Company desires to issue and sell $400,000,000 aggregate principal amount of the Notes as of the date hereof; 

WHEREAS, the Company desires to establish the form and terms of the Notes; 

WHEREAS, all things necessary to make this Seventh Supplemental Indenture a legal and binding supplement to the Base Indenture in accordance
with its terms and the terms of the Base Indenture have been done; 
 WHEREAS, the Company and the Parent Guarantor have complied with all
conditions precedent provided for in the Base Indenture relating to this Seventh Supplemental Indenture; and 







 WHEREAS, the Company has requested that the Trustee execute and deliver this Seventh Supplemental
Indenture. 
 NOW, THEREFORE: 

For and in consideration of the premises stated herein and the purchase of the Notes by the Holders thereof, the Company, the Parent
Guarantor, the Subsidiary Guarantors and the Trustee covenant and agree, for the equal and proportionate benefit of the Holders of the Notes, as follows: 

ARTICLE 1 
 SCOPE OF SEVENTH
SUPPLEMENTAL INDENTURE 
 Section 1.01.    Scope. This Seventh Supplemental Indenture constitutes a
supplement to the Base Indenture and an integral part of the Indenture and shall be read together with the Base Indenture as though all the provisions thereof are contained in one instrument. Except as expressly amended by the Fourth Supplemental
Indenture, the Sixth Supplemental Indenture and this Seventh Supplemental Indenture, the terms and provisions of the Base Indenture shall remain in full force and effect. Notwithstanding the foregoing, this Seventh Supplemental Indenture shall only
apply to the Notes. 
 ARTICLE 2 

DEFINITIONS 

Section 2.01.    Definitions and Other Provisions of General Application. For all purposes of this Seventh
Supplemental Indenture unless otherwise specified herein: 
 (a)    all terms used in this Seventh Supplemental
Indenture which are not otherwise defined herein shall have the meanings they are given in the Base Indenture; 

(b)    the provisions of general application stated in Section 1.04 of the Base Indenture shall apply to this Seventh
Supplemental Indenture, except that the words “herein,” “hereof,” “hereto” and “hereunder” and other words of similar import refer to this Seventh Supplemental Indenture as a whole
and not to the Base Indenture or any particular Article, Section or other subdivision of the Base Indenture or this Seventh Supplemental Indenture; 

(c)    Section 1.01 of the Base Indenture is amended and supplemented, solely with respect to the Notes, by inserting the
following additional defined terms in their appropriate alphabetical positions: 
 “Attributable Debt,” in respect of any
Sale and Leaseback Transaction, means, as of the time of determination, the total obligation (discounted to present value at the rate per annum equal to the discount rate which would be applicable to a capital lease obligation with like term in
accordance with GAAP) of the lessee for rental payments (other than amounts required to be paid on account of property taxes, maintenance, repairs, insurance, water rates and other items which do not constitute payments for property rights) during
the remaining portion of the initial term of the lease included in such Sale and Leaseback Transaction. 

  
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 “Board of Directors” means the board of directors of the Parent Guarantor. 

“Change of Control” means such time as: 

(1)    the direct or indirect sale, transfer, conveyance or other disposition (other than by way of merger or
consolidation), in one or a series of related transactions, of all or substantially all of the properties or assets of the Company and its Subsidiaries, taken as a whole, to any “person” (as that term is used in Section 13(d)(3) of the
Exchange Act); 
 (2)    a “person” or “group” (within the meaning of Sections 13(d) and 14(d)(2) of
the Exchange Act) becomes the ultimate “beneficial owner” (as defined in Rule 13d-3 under the Exchange Act) of more than 50% of the total voting power of the Voting Stock of the Parent Guarantor on a
fully diluted basis; 
 (3)    the adoption of a plan relating to the liquidation or dissolution of the Company or the
Parent Guarantor; 
 (4)    individuals who on the Closing Date constitute the Board of Directors (together with any new
directors whose election by the Board of Directors or whose nomination by the Board of Directors for election by the Parent Guarantor’s stockholders was approved by a vote of a majority of the members of the Board of Directors then in office
who either were members of the Board of Directors on the Closing Date or whose election or nomination for election was previously so approved) cease for any reason to constitute a majority of the members of the Board of Directors then in office;

 (5)    the Company or the Parent Guarantor consolidates with, or merges with or into, any Person, or any Person
consolidates with, or merges with or into the Company or the Parent Guarantor, in any such event pursuant to a transaction in which any of the outstanding Voting Stock of the Company or the Parent Guarantor, as the case may be, or such other Person
is converted into or exchanged for cash, securities or other property, other than any such transaction where (A) the Voting Stock of the Company or the Parent Guarantor outstanding immediately prior to such transaction is converted into or
exchanged for Voting Stock of the surviving or transferee Person constituting a majority of the outstanding shares of such Voting Stock of such surviving or transferee Person (immediately after giving effect to such issuance) and
(B) immediately after such transaction, no “person” or “group” (as such terms are used in Sections 13(d) and 14(d) of the Exchange Act) becomes, directly or indirectly, the beneficial owner of 50% or more of the voting power
of the Voting Stock of the surviving or transferee Person; or 
 (6)    the Parent Guarantor fails to own 100% of the
Capital Stock of the Company; provided, however, that it shall not be deemed a Change of Control if the Parent Guarantor merges into the Company, except that in such case, the Company shall be substituted for the Parent Guarantor for
purposes of this definition of “Change of Control,” and this clause (6) shall no longer be applicable. 

  
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 “Change of Control Repurchase Event” means the occurrence of both a Change of
Control and a Ratings Event. 
 “Closing Date” means March 23, 2017. 

“Consolidated Net Tangible Assets” means the total assets of the Parent Guarantor and its Subsidiaries after deducting
therefrom all intangible assets, current liabilities (excluding any thereof which are by their terms extendible or renewable at the option of the obligor thereon to a time more than 12 months after the time as of which the amount thereof is being
computed) and minority interests, if any, in any assets of the Subsidiaries, all as would be set forth on the most recently available quarterly or annual consolidated balance sheet of the Parent Guarantor and its Subsidiaries, prepared in conformity
with GAAP. For purposes of calculating Consolidated Net Tangible Assets, pro forma effect shall be given on the date of calculation to the items set forth in the definition of “Fixed Charge Coverage Ratio.” 

“EBITDA” shall be determined on a last-in
first-out inventory method and consolidated basis for the Parent Guarantor and its Subsidiaries in conformity with GAAP, as the sum, without duplication, of net income, calculated before interest expense,
provision for income taxes, depreciation and amortization expense, losses arising from the sale of capital assets, other non-cash losses and charges deducted in the calculation of net income (other than any
such non-cash item to the extent that it represents an accrual of or reserve for cash expenditures in any future period), any non-recurring, unusual or extraordinary
losses or charges, all plant consolidation, shut-down or idling costs or charges, including any contract termination or union settlement charges, all write-offs and writedowns and all non-cash corridor charges
associated with pensions and other post-retirement benefit obligations (in each case, only to the extent included in determining net income), less non-cash gains included in the calculation of net income
(other than any such non-cash item to the extent that it will result in the receipt of cash payments within 12 months after the date on which it was accrued), gains arising from the sale of capital assets,
gains arising from the write-up of assets, any non-recurring, unusual or extraordinary gains and all non-cash corridor gains
associated with pensions and other postretirement benefit obligations (in each case, only to the extent included in determining net income). 

“Exchange Act” means the Securities Exchange Act of 1934, as amended. 

“Fixed Charge Coverage Ratio” means, on any date (the “transaction date”), the ratio of (a) the
aggregate amount of EBITDA for the most recent four fiscal quarters immediately prior to the transaction date for which internal financial statements are available (the “reference period”) to (b) the aggregate Fixed Charges
during such reference period. 
 In making the foregoing calculation, 

(1) the Fixed Charge Coverage Ratio shall be calculated for the Parent Guarantor and its Subsidiaries on a consolidated basis; 

  
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 (2) pro forma effect will be given to any Indebtedness incurred during or after the reference
period and on or prior to such date of determination to the extent the Indebtedness is outstanding or is to be incurred on such date as if the Indebtedness had been incurred on the first day of the reference period; 

(3) pro forma calculations of interest on Indebtedness bearing a floating interest rate will be made as if the rate in effect on the
transaction date (taking into account any hedging agreement applicable to the Indebtedness if the hedging agreement has a remaining term of at least 12 months) had been the applicable rate for the entire reference period; 

(4) Fixed Charges related to any Indebtedness no longer outstanding or to be repaid or redeemed on the transaction date, except for interest
expense accrued during the reference period under a revolving credit to the extent of the commitment thereunder (or under any successor revolving credit) in effect on the transaction date, will be excluded; and 

(5) any acquisitions, dispositions, amalgamations, mergers, consolidations and discontinued operations (as determined in accordance with
GAAP), that the Company or any of its Subsidiaries has made during the reference period or subsequent to such reference period and on or prior to or simultaneously with the Fixed Charge Coverage Ratio calculation date shall be calculated on a pro
forma basis assuming that all such acquisitions, dispositions, amalgamations, mergers, consolidations and discontinued operations (and the change in any associated fixed charge obligations and the change in EBITDA resulting therefrom) had occurred
on the first day of the reference period in accordance with Article 11 of Regulation S-X under the Exchange Act. If since the beginning of such period any Person that subsequently became a Subsidiary or was
merged, amalgamated or consolidated with or into the Company or any of its Subsidiaries since the beginning of such period shall have made any acquisition, disposition, amalgamation, merger, consolidation or discontinued operation that would have
required adjustment pursuant to this definition, then the Fixed Charge Coverage Ratio shall be calculated giving pro forma effect thereto for such period as if such acquisition, disposition, discontinued operation, merger, amalgamation or
consolidation had occurred at the beginning of the applicable four-quarter period. 
 “Fixed Charges” means the sum of
consolidated cash interest expense as determined in accordance with GAAP and cash dividends on any preferred stock. 
 “Foreign
Subsidiary” means any Subsidiary that is not organized or existing under the laws of the United States, any state thereof, the District of Columbia, or any territory thereof. 

“Funded Debt” means all Indebtedness having a maturity of more than 12 months from the date as of which the determination is
made or having a maturity of 12 months or less but by its terms being renewable or extendable beyond 12 months from such date at the option of the borrower, but excluding any such Indebtedness owed to the Parent Guarantor or a Subsidiary of the
Parent Guarantor. 

  
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 “Guarantor” means the Parent Guarantor and each Subsidiary Guarantor. 

“Investment Grade” means a rating of Baa3 or better by Moody’s (or its equivalent under any successor Rating Categories
of Moody’s), a rating of BBB- or better by S&P (or its equivalent under any successor Rating Categories of S&P) and the equivalent Investment Grade credit rating from any additional Rating Agency
or Rating Agencies selected by the Company. 
 “Junior Lien Obligations” means any Indebtedness of the Company or any
Guarantor which is or will be secured by a Lien on the collateral securing the Secured Notes and the guarantees thereof or any extension, renewal, replacement or refunding thereof secured pursuant to Section 5.01(b)(viii) (or any other Indebtedness
secured on a first lien basis by liens on the Principal Property or shares of stock or other equity interests or Indebtedness subject to the provisions in Section 5.01(a) (“First Lien Collateral”) on a basis that is junior to the
lien on such Indebtedness); provided that if no other secured Indebtedness secured by Principal Property or such shares of stock or other equity interests or Indebtedness is outstanding at such time, it is understood that such Junior Lien
Obligations would be secured on a senior lien basis at such time, but the terms thereof must provide that the Liens securing such Junior Lien Obligations would be subordinated to any liens on First Lien Collateral that may be incurred in the future
to secure other Indebtedness that is incurred and secured pursuant to Section 5.01(c). 
 “Lien” means, with respect to any
property or assets, any mortgage or deed of trust, pledge, hypothecation, assignment, security interest, lien, encumbrance, or any other security arrangement of any kind or nature whatsoever on or with respect to such property or assets (including
any conditional sale or other title retention agreement having substantially the same economic effect as any of the foregoing). 

“Moody’s” means Moody’s Investors Service Inc. 

“Note Guarantee” means a Guarantee of the obligations of the Company under the Notes and the Indenture in respect of the
Notes. 
 “Offer to Purchase” means an offer to purchase Notes by the Company from the Holders of the Notes commenced by
mailing a notice, which will govern the offer, by first class mail to the Trustee and each Holder of a Note stating: 

(1)    that all Notes validly tendered will be accepted for payment on a pro rata basis; 

(2)    the Change of Control Payment and the date of purchase of the Notes, which shall be at least 30 days but not more
than 60 days from the date such notice is mailed, other than as may be required by law (the “Change of Control Payment Date”); 

(3)    that any Note not tendered will continue to accrue interest pursuant to its terms; 

  
 6 








 (4)    that, unless the Company defaults in the payment of the Change of
Control Payment, any Note accepted for payment pursuant to the Offer to Purchase shall cease to accrue interest on and after the Change of Control Payment Date; 

(5)    that Holders of the Notes electing to have a Note purchased pursuant to the Offer to Purchase will be required to
surrender the Note, together with the form entitled “Option of the Holder to Elect Purchase” on the reverse side of the Note completed, to the Paying Agent at the address specified in the notice prior to the close of business on the
Business Day immediately preceding the Change of Control Payment Date; 
 (6)    that Holders of the Notes will be
entitled to withdraw their election if the Paying Agent receives, not later than the close of business on the third Business Day immediately preceding the Payment Date, a telegram, facsimile transmission or letter setting forth the name of such
Holder, the principal amount of Notes delivered for purchase and a statement that such Holder is withdrawing his election to have such Notes purchased; and 

(7)    that Holders of the Notes whose Notes are being purchased only in part will be issued new Notes equal in principal
amount to the unpurchased portion of the Notes surrendered; provided that each Note purchased and each new Note issued shall be in a principal amount of $2,000 or integral multiples of $1,000 in excess thereof. 

On the Change of Control Payment Date, the Company shall (a) accept for payment on a pro rata basis Notes or portions thereof tendered
pursuant to an Offer to Purchase; (b) deposit with the Paying Agent money sufficient to pay the purchase price of all notes or portions thereof so accepted; and (c) deliver, or cause to be delivered, to the Trustee all notes or portions
thereof so accepted together with an Officers’ Certificate specifying the Notes or portions thereof accepted for payment by the Company. The Paying Agent shall promptly mail to the Holders of Notes so accepted payment in an amount equal to the
purchase price, and the Trustee shall promptly authenticate and mail to such Holders a new note equal in principal amount to any unpurchased portion of the note surrendered; provided that each note purchased and each new note issued shall be in a
principal amount of $2,000 or integral multiples of $1,000 in excess thereof. The Company will publicly announce the results of an Offer to Purchase as soon as practicable after the Payment Date. The Trustee shall act as the Paying Agent for an
Offer to Purchase. The Company will comply with Rule 14e-1 under the Exchange Act and any other securities laws and regulations thereunder to the extent such laws and regulations are applicable in
the event that the Company is required to repurchase Notes pursuant to an Offer to Purchase. 
 “Principal Property” means
any domestic blast furnace or steel producing facility, or casters that are part of a plant that includes such a facility, in each case located in the United States, having a net book value in excess of 1% of Consolidated Net Tangible Assets at the
time of determination. 
 “Rating Agency” means (1) each of Moody’s and S&P and (2) if either of
Moody’s or S&P ceases to rate the Notes or fails to make a rating of the Notes publicly 

  
 7 








 
available for reasons outside of the control of the Company, a “nationally recognized statistical rating organization” as defined in Section 3(a)(62) of the Exchange Act, selected by
the Company (as certified by a resolution of the board of directors of the Company) as a replacement agency for Moody’s or S&P, or both, as the case may be. 

“Rating Category” means (i) with respect to S&P, any of the following categories: BBB, BB, B, CCC, CC, C and D (or
equivalent successor categories); (ii) with respect to Moody’s, any of the following categories: Baa, Ba, B, Caa, Ca, C and D (or equivalent successor categories); and (iii) the equivalent of any such category of S&P or Moody’s
used by another Rating Agency. In determining whether the rating of the Notes has decreased by one or more gradations, gradations within Rating Categories (+ and - for S&P; 1, 2 and 3 for Moody’s; or the equivalent gradations for another
Rating Agency) shall be taken into account (e.g., with respect to S&P, a decline in a rating from BB+ to BB, as well as from BB- to B+, will constitute a decrease of one gradation). 

“Rating Date” means the date that is 60 days prior to the earlier of (i) a Change of Control or (ii) public notice
of the occurrence of a Change of Control or of the intention by the Company or the Parent Guarantor, as applicable, to effect a Change of Control. 

“Ratings Event” means the occurrence of the events described in (a) or (b) of this definition on, or within 60 days
after the earlier of, (i) the occurrence of a Change of Control or (ii) public notice of the occurrence of a Change of Control or the intention by the Company or the Parent Guarantor, as applicable, to effect a Change of Control (which
period shall be extended so long as the rating of the Notes is under publicly announced consideration for a possible downgrade by any of the Rating Agencies): (a) if the Notes are rated by both Rating Agencies on the Rating Date as Investment Grade,
the rating of the Notes shall be reduced so that the Notes are rated below Investment Grade by both Rating Agencies, or (b) if the Notes are rated below Investment Grade by at least one Rating Agency, the ratings of the Notes by both Rating
Agencies shall be decreased by one or more gradations (including gradations within Rating Categories, as well as between Rating Categories) and the Notes are then rated below Investment Grade by both Rating Agencies. 

Notwithstanding the foregoing, a Ratings Event otherwise arising by virtue of a particular reduction in rating shall not be deemed to have
occurred in respect of a particular Change of Control (and thus shall not be deemed a Ratings Event for purposes of the definition of Change of Control Repurchase Event hereunder) if the Rating Agencies making the reduction in rating to which this
definition would otherwise apply do not announce or publicly confirm or inform the Trustee in writing at its request that the reduction was the result, in whole or in part, of any event or circumstance comprised of or arising as a result of, or in
respect of, the applicable Change of Control (whether or not the applicable Change of Control shall have occurred at the time of the Ratings Event). 

“Receivables Facility” means one or more receivables financing facilities, as amended, supplemented, modified, extended,
renewed, restated or refunded from time to 

  
 8 








 
time, the obligations of which are non-recourse (except for customary representations, warranties, covenants and indemnities made in connection with such
facilities) to the Company or any of its Restricted Subsidiaries (other than a Receivables Subsidiary) pursuant to which the Company or any of its Restricted Subsidiaries sells their accounts receivable to either (a) a Person that is not a
Restricted Subsidiary or (b) a Receivables Subsidiary that in turn sells its accounts receivable to a Person that is not a Restricted Subsidiary. 

“Receivables Subsidiary” means any Subsidiary formed for the purpose of, and that solely engages only in one or more
Receivables Facilities or other activities reasonably related thereto. 
 “Restricted Subsidiary” means any Subsidiary
other than an Unrestricted Subsidiary. 
 “S&P” means Standard & Poor Financial Services LLC, a subsidiary of
S&P Global Inc. or its successor. 
 “Sale and Leaseback Transaction” means any arrangement with any Person providing
for the leasing to the Company or any Subsidiary of the Company of any Principal Property, which Principal Property has been or is to be sold or transferred by the Company or any Subsidiary of the Company to such Person. 

“Secured Notes” means the $380 million outstanding principal amount of 7.50% Secured Notes due 2023 of the Company
outstanding on the issue date of the Notes. 
 “Subsidiary Guarantor” means each Subsidiary that Guarantees the
Company’s obligations under the Notes and the Indenture in respect of the Notes, and as of the Closing Date includes AK Tube, AK Steel Properties and MSC. 

“Unrestricted Subsidiary” means (i) any Foreign Subsidiary, (ii) any Receivables Subsidiary and (iii) any
Subsidiary of the Parent Guarantor created after the Closing Date, at least 10% of the Voting Stock of which is owned by Persons other than the Parent Guarantor or a Subsidiary thereof; provided that (a) such Subsidiary does not engage
in the business of the Company as conducted on the Closing Date (but shall engage in any extension thereof or activities incidental or related thereto) and (b) in the event (1) any such Subsidiary Guarantees Indebtedness of the Company in
an aggregate amount in excess of $50 million or (2) the Company or any of its Subsidiaries (other than an Unrestricted Subsidiary) contributes or otherwise transfers (other than a sale for fair market value) any Principal Property
(including shares of stock of a Subsidiary that owns the Principal Property) or the proceeds of any sale of Principal Property to such Subsidiary, in either case such Subsidiary shall cease to be an Unrestricted Subsidiary. 

“Voting Stock” means with respect to any Person, Capital Stock of any class or kind ordinarily having the power to vote for
the election of directors, managers or other voting members of the governing body of such Person. 

  
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 Section 2.02.    Other Definitions. Each of the following terms
is defined in the section set forth opposite such term: 
  

			
	Term	  	Section
	Additional Refinancing Amount	  	Section 5.01(b)(viii)
	Applicable Premium Deficit	  	Section 8.02(a)
	Change of Control Payment	  	Section 4.01
	DTC	  	Section 3.02(s)
	Non-Guarantor Subsidiary Debt	  	Section 5.02(a)

 ARTICLE 3 

FORM AND TERMS OF THE NOTES 

Section 3.01.    Form and Dating. 

(a)    The Notes shall be substantially in the form of Exhibit A attached hereto. The Notes shall be executed on
behalf of the Company by one Officer of the Company. The Notes may have a legend or legends or endorsements as may be required to comply with any law or with any rules of any securities exchange or usage. The Notes shall be dated the date of their
authentication. The Notes and any beneficial interest in the Notes shall be in minimum denominations of $2,000 and integral multiples of $1,000 in excess thereof. 

(b)    The terms contained in the Notes shall constitute, and are hereby expressly made, a part of the Indenture as
supplemented by the Fourth Supplemental Indenture, the Sixth Supplemental Indenture and this Seventh Supplemental Indenture and the Company, the Parent Guarantor, the Subsidiary Guarantors and the Trustee, by their execution and delivery of this
Seventh Supplemental Indenture, expressly agree to such terms and provisions and to be bound thereby. 

Section 3.02.    Terms of the Notes. The following terms relating to the Notes are hereby established: 

(a)    Title. The Notes shall constitute a series of Securities having the title “7.00% Senior Notes due
2027.” 
 (b)    Principal Amount. The aggregate principal amount of the Notes that may be authenticated and
delivered under the Indenture, as amended hereby, shall be $400,000,000 on the Closing Date. Provided that no Event of Default has occurred and is continuing with respect to the Notes, the Company may, without notice to or the consent of the
Holders, create and issue additional Securities having the same terms as, and ranking equally and ratably with, the Notes in all respects and so that such additional Notes will be consolidated and form a single series with, and have the same terms
as to status, redemption or otherwise as, the Notes initially issued; provided that if the additional Securities are not fungible with the Notes for U.S. federal income tax purposes, the additional Securities will have a separate CUSIP
number. 

  
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 (c)    Maturity Date. The entire outstanding Principal of the Notes
shall be payable on March 15, 2027. 
 (d)    Interest Rate. The rate at which the Notes shall bear interest
shall be 7.00% per annum; the date from which interest shall accrue on the Notes shall be March 23, 2017 or the most recent interest payment date to which interest has been paid or duly provided for; the interest payment dates for the Notes
shall be March 15 and September 15 of each year, beginning September 15, 2017; the interest so payable and punctually paid or duly provided for, on any interest payment date, will be paid to the Person in whose names the Notes are
registered at the close of business on the record date for such interest, which shall be the March 1 or September 1 as the case may be, immediately preceding such interest payment date, except that interest payable at maturity will be paid
to the same Persons to whom Principal of the Notes is payable; the interest will be computed on the basis of a 360-day year consisting of twelve 30-day months. 

(e)    Place of Payment of Principal and Interest. Section 4.02 of the Base Indenture shall apply to the
Notes. 
 (f)    Optional Redemption. The Notes shall be redeemable as specified in the form of Note attached as
Exhibit A hereto, and Article 3 of the Base Indenture shall apply to any such redemption. 
 (g)    Mandatory
Redemption, Repurchase or Repayment. Except as provided pursuant to Article 4, the Company shall have no other obligation to redeem, purchase or repay the Notes pursuant to any mandatory redemption, sinking fund or analogous provisions or at the
option of a Holder thereof. 
 (h)    Denomination. The Notes shall be denominated as set forth in the Base
Indenture. 
 (i)    Acceleration. 100% of the principal amount of the Notes shall be payable upon declaration of
acceleration of the maturity thereof. 
 (j)    Currency of the Notes. The Notes shall be denominated, and
payment of Principal and interest of the Notes shall be payable in, the currency of the United States of America. 

(k)    Currency of Payment. The Principal of and interest on the Notes shall be payable in the currency of the
United States of America. 
 (l)    Registered Form. The Notes shall be issuable as Registered Global Securities.
Section 2.07 of the Base Indenture, as modified by Section 3.02(n) hereof, shall apply to the Notes. 

  
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 (m)    Transfer and Exchange. Section 2.07 of the Base Indenture
is amended and supplemented by adding the following at the end of the eighth paragraph thereof: 
 “If an Event of Default has occurred
and is continuing and the Trustee has received a request from the Depositary, the Trustee will promptly exchange each beneficial interest in the Registered Global Securities for definitive Registered Securities in authorized denominations having an
equal aggregate principal amount registered in the name of the owner of such beneficial interest, as identified to the Trustee by the Depositary, and thereupon the Registered Global Securities will be deemed canceled. In addition, beneficial
interests in a Registered Global Security may be exchanged for definitive Registered Securities upon prior written notice given to the Trustee by or on behalf of the Depositary in accordance with the Depositary’s procedures, in which case the
Trustee will promptly exchange beneficial interests for definitive Registered Securities in authorized denominations having an equal principal amount registered in the name of the owner of such beneficial interest.” 

(n)    Exchange or Conversion. The Notes shall not be exchangeable for or convertible into the common stock of the
Company or any other security. 
 (o)    Additional Amounts. The Company will not pay any additional amounts on
the Notes. 
 (p)    Definitive Form. The Notes may be issued in definitive form pursuant to the terms of the
Base Indenture as modified by Section 3.02(n) above. 
 (q)    Trustee. The trustee shall be U.S. Bank
National Association; and the Paying Agent and Authenticating Agent shall initially be the Trustee. 

(r)    Satisfaction and Discharge. Article 10 of the Base Indenture, as modified by Article 8 hereof, shall apply
to the Notes. 
 (s)    Depositary. The Depositary for any Notes issued as Global Registered Securities shall be
The Depository Trust Company in The City of New York (“DTC”) or any successor Depositary appointed by the Company within 90 days of the termination of services of DTC (or any successor to DTC). 

(t)    Events of Default. Article 7 of the Base Indenture, as modified by Article 7 hereof, shall apply to the
Notes. 
 (u)    Covenants. The covenants set forth in Article 4 of the Base Indenture and Article 5 of this
Seventh Supplemental Indenture shall apply to the Notes. 
 (v)    Additional Terms. Other terms applicable to
the Notes are as otherwise provided for below. 
 ARTICLE 4 

CHANGE OF CONTROL 

Section 4.01.    Redemption Upon Change of Control. (a) Within 30 days following the date upon which any
Change of Control Repurchase Event occurs, or at the 

  
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Company’s option, prior to any Change of Control Repurchase Event if a definitive agreement is in place for the Change of Control at the time of making the Offer to Purchase pursuant to the
Change of Control Repurchase Event, the Company shall commence an Offer to Purchase at a purchase price equal to 101% of the aggregate principal amount of the Notes repurchased, plus accrued and unpaid interest, if any, to the date of repurchase
(the “Change of Control Payment”), subject to the rights of Holders of Notes on the relevant record date to receive interest due on the relevant interest payment date. 

(b)    On the Change of Control Payment Date, the Company will, to the extent lawful: 

(i)    accept for payment on a pro rata basis all Notes or portions of Notes properly tendered pursuant to
an Offer to Purchase not validly withdrawn; 
 (ii)    deposit with the Paying Agent the required payment
for all properly tendered Notes or portions of Notes so accepted; and 
 (iii)    deliver or cause to be
delivered to the Trustee the repurchased Notes or portions thereof so accepted, accompanied by an Officers’ Certificate stating, among other things, the aggregate principal amount of repurchased Notes. 

(c)    Following the Change of Control Payment Date: 

(i)    the Paying Agent shall promptly mail to the Holders of Notes so accepted payment in an amount equal
to the purchase price, and the Trustee shall promptly authenticate and mail to such Holders a new Note equal in principal amount to any unpurchased portion of the Note surrendered; provided that each Note purchased and each new Note issued
shall be in a principal amount of $2,000 or integral multiples of $1,000 in excess thereof; and 

(ii)    the Company will publicly announce the results of an Offer to Purchase as soon as practicable after
the Change of Control Payment Date. 
 (d)    The Trustee shall act as the Paying Agent for an Offer to Purchase. 

(e)    The Company will not be required to make an Offer to Purchase upon the occurrence of a Change of Control Repurchase
Event if a third party makes an offer to purchase the Notes in the manner, at the times and price, and otherwise in compliance with the requirements of the Indenture applicable to an Offer to Purchase made by the Company and the third party
purchases all Notes validly tendered and not withdrawn in such offer to purchase. 
 (f)    Notwithstanding anything to
the contrary herein, the Company may make an Offer to Purchase upon the occurrence of a Change of Control Repurchase Event in advance of a Change of Control, conditional upon such Change of Control Repurchase Event, if a definitive agreement is in
place for the Change of Control at the time of making the Offer to Purchase, in which case the notice will state that the Offer to Purchase is conditioned on the Change of Control Repurchase Event being consummated on or prior to the Change of
Control Payment Date. 

  
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 (g)    The Company will comply with the requirements of Rule 14e-1 under the Exchange Act and any other securities laws and regulations thereunder, to the extent those laws and regulations are applicable, in connection with the repurchase of Notes as a result of a Change of
Control Repurchase Event. To the extent that the provisions of any such securities laws or regulations conflict with this Section 4.01, the Company will comply with those securities laws and regulations and will not be deemed to have breached
the Company’s obligations under this Section 4.01 by virtue of any such conflict. 
 ARTICLE 5 

COVENANTS 
 In addition to the
covenants set forth in the Base Indenture, the Company agrees for the benefit of the Holders of the Notes that: 

Section 5.01.    Limitation On Liens. (a) So long as any Notes are outstanding, the Parent Guarantor will
not, and will not permit any of its Subsidiaries to, create, incur, issue, assume or Guarantee any Indebtedness secured by a Lien upon (a) any Principal Property of the Company or any Principal Property of a Subsidiary of the Company or
(b) any shares of stock or other equity interests or Indebtedness of any Subsidiary of the Company that owns a Principal Property (whether such Principal Property, shares of stock or other equity interests or Indebtedness is now existing or
owned or hereafter created or acquired) or any shares of stock or other equity interests or Indebtedness of the Company, in each case, without effectively providing concurrently that the Notes are secured equally and ratably with or, at the Parent
Guarantor’s option, prior to such Indebtedness, so long as such Indebtedness shall be so secured. 
 (b)    This
restriction does not apply to, and there shall be excluded from Indebtedness in any computation under such restriction, Indebtedness secured by: 

(i)    Liens on any property or assets existing at the time of the acquisition thereof by the Company or
any of its Subsidiaries and not incurred in contemplation of such acquisition; 
 (ii)    Liens on
property or assets of a Person existing at the time such Person is merged into or consolidated with the Company or any of its Subsidiaries or at the time of a sale, lease or other disposition of the properties and assets of such Person (or a
division thereof) as an entirety or substantially as an entirety to the Company or any of its Subsidiaries; provided that any such Lien does not extend to any Principal Property owned by the Company or any of its Subsidiaries immediately
prior to such merger, consolidation, sale, lease or disposition and not incurred in contemplation of such acquisition; 

  
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 (iii)    Liens on property or assets of a Person existing at
the time such Person becomes a Subsidiary of the Company and not incurred in contemplation of such acquisition; 

(iv)    Liens in favor of the Company or any Guarantor; 

(v)    Liens on property or assets (including shares of Capital Stock or Indebtedness of any Subsidiary
formed to acquire, construct, develop or improve such property) to secure all or part of the cost of acquisition, construction, development or improvement of such property, or to secure Indebtedness incurred to provide funds for any such purpose;
provided that the commitment of the creditor to extend the credit secured by any such Lien shall have been obtained no later than 360 days after the later of (a) the completion of the acquisition, construction, development or improvement
of such property or assets or (b) the placing in operation of such property or assets; 

(vi)    Liens in favor of the United States of America or any State thereof, or any department, agency or
instrumentality or political subdivision thereof, to secure partial, progress, advance or other payments; 

(vii)    Liens securing the Secured Notes and the guarantees thereof; 

(viii)    Liens existing on the date of the Indenture or any extension, renewal, replacement or refunding
of any Indebtedness secured by a Lien existing on the date of the Indenture or referred to in clauses (i), (ii), (iii), (v), (vii) or (ix) or incurred pursuant to Section 5.01(c); provided that (A) any such extension, renewal,
replacement or refunding of such Indebtedness shall be created within 360 days of repaying the Indebtedness secured by the Lien referred to in this clause or clauses (i), (ii), (iii), (v), (vii) or (ix) or within 30 days in the case of Section
5.01(c) and (B) the principal amount of the Indebtedness secured thereby and not otherwise authorized by clauses (i), (ii), (iii), (v), (vii) or (ix) or Section 5.01(c) shall not exceed the principal amount of Indebtedness plus any premium
or fee or accrued and unpaid interest payable (any such principal in respect of premium, fees or interest, the “Additional Refinancing Amount”), in connection with any such extension, renewal, replacement or refunding, so secured at
the time of such extension, renewal, replacement or refunding, provided further that any Liens on any extension, renewal, replacement or refunding of Junior Lien Obligations incurred pursuant to clause (ix) below pursuant to this
clause (viii) shall constitute Junior Lien Obligations; and 
 (ix)    Liens on assets constituting
collateral securing Junior Lien Obligations, provided that the aggregate principal amount of Indebtedness so secured does not exceed, together with any Indebtedness incurred pursuant to clause (viii) to extend, renew, replace or refund
any Indebtedness incurred pursuant to this clause (ix) (but excluding any Additional Refinancing Amount), (x) $500.0 million or (y) if greater, an amount which after giving effect to the incurrence of such Indebtedness so secured, would
not cause the Parent Guarantor’s Fixed Charge Coverage Ratio to be less than 2.0 to 1.0. 

  
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 (c)    Notwithstanding the restrictions described above, the Parent Guarantor
and any of its Subsidiaries may create, incur, issue, assume or Guarantee Indebtedness secured by Liens, without equally and ratably securing the Notes, if at the time of such creation, incurrence, issuance, assumption or Guarantee, after giving
effect thereto and to the retirement of any Indebtedness which is concurrently being retired, the aggregate amount of all such Indebtedness secured by Liens which would otherwise be subject to such restrictions (other than any Indebtedness secured
by Liens permitted as described in clauses (i) through (ix) of Section 5.01(b) plus the aggregate amount (without duplication) of (x) all Non-Guarantor Subsidiary Debt (other than Non-Guarantor Subsidiary Debt described in clauses (i) through (vi) of Section 5.02(b)) and (y) all Attributable Debt of the Company and any of its Subsidiaries in respect of Sale and Leaseback
Transactions (with the exception of such transactions which are permitted under clauses (i) through (iv) of Section 5.03) does not exceed an amount equal to (x) 15% of Consolidated Net Tangible Assets less (y) the aggregate principal
amount of the Secured Notes outstanding at such time and the amount of (i) any Indebtedness incurred to extend, renew, replace or refund the Secured Notes secured by Liens pursuant to Section 5.01(b)(viii), (ii) any Indebtedness incurred
pursuant to Section 5.01(b)(viii) to refinance Indebtedness incurred pursuant to this paragraph and (iii) any Indebtedness incurred pursuant to Section 5.02(b)(v)Section 5.02(b)(iv) to refinance Indebtedness incurred pursuant to Section 5.02(c)
(but excluding any Additional Refinancing Amount). 
 Section 5.02.    Limitation On Subsidiary Debt.
(a) So long as any Notes are outstanding, the Company will not permit any of its Restricted Subsidiaries that is not a Subsidiary Guarantor to create, assume, incur, Guarantee or otherwise become liable for or suffer to exist any Indebtedness
(any Indebtedness of a non- Guarantor Subsidiary of the Company, “Non-Guarantor Subsidiary Debt”), without concurrently Guaranteeing the payment of the
Principal of, premium, if any, and interest on the Notes on an unsecured unsubordinated basis. 
 (b)    This
restriction does not apply to, and there shall be excluded from Indebtedness in any computation under such restriction, Non-Guarantor Subsidiary Debt constituting: 

(i)    Indebtedness of a Person existing at the time such Person is merged into or consolidated with any
Restricted Subsidiary of the Company or at the time of a sale, lease or other disposition of the properties and assets of such Person (or a division thereof) as an entirety or substantially as an entirety to any Restricted Subsidiary of the Company
and is assumed by such Restricted Subsidiary; provided that any Indebtedness was not incurred in contemplation thereof and is not Guaranteed by any other Subsidiary of the Company; 

(ii)    Indebtedness of a Person existing at the time such Person becomes a Restricted Subsidiary of the
Company; provided that any Indebtedness was not incurred in contemplation thereof; 

  
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 (iii)    Indebtedness owed to the Company or any Guarantor;

 (iv)    Indebtedness outstanding on the date of the Indenture or any extension, renewal, replacement
or refunding of any Indebtedness existing on the date of the Indenture or referred to in clauses (i), (ii) or (iii) or incurred pursuant to Section 5.02(c); provided that any such extension, renewal, replacement or refunding of
such Indebtedness shall be created within 360 days of repaying the Indebtedness referred to in this clause or clauses (i), (ii) or (iii) above or within 30 days in the case of Section 5.02(c) and the principal amount of the
Indebtedness shall not exceed the principal amount of Indebtedness plus any premium or fee payable in connection with any such extension, renewal, replacement or refunding, so secured at the time of such extension, renewal, replacement or refunding;

 (v)    Indebtedness in respect of a Receivables Facility; and 

(vi)    Indebtedness in an amount of not more than $5.0 million at any time outstanding. 

(c)    Notwithstanding the limitations on Non-Guarantor Subsidiary Debt described
in Section 5.02(a), the Company and any of its Restricted Subsidiaries may create, incur, issue, assume or Guarantee Non-Guarantor Subsidiary Debt, without Guaranteeing the Notes, if at the time of such
creation, incurrence, issuance, assumption or Guarantee, after giving effect thereto and to the retirement of any Indebtedness which is concurrently being retired, the aggregate amount of all such
Non-Guarantor Subsidiary Debt which would otherwise be subject to such restrictions (other than Non-Guarantor Subsidiary Debt which is described in clauses
(i) through (v) of Section 5.02(b)) plus the aggregate amount (without duplication) of (x) all Indebtedness secured by Liens (not including any such Indebtedness secured by Liens described in clauses (i) through (ix) of Section
5.01(b)) and (y) all Attributable Debt of the Company and any of its Subsidiaries in respect of Sale and Leaseback Transactions (with the exception of such transactions which are permitted under clauses (i) through (iv) of
Section 5.03) does not exceed an amount equal to (x) 15% of Consolidated Net Tangible Assets less (y) the aggregate principal amount of the Secured Notes outstanding at such time and the amount of (i) any Indebtedness incurred to
extend, renew, replace or refund the Secured Notes secured by Liens pursuant to Section 5.01(b)(viii), (ii) any Indebtedness incurred pursuant to Section 5.01(b)(viii) above to refinance Indebtedness incurred pursuant to Section 5.01(c) and
(iii) any Indebtedness incurred pursuant to Section 5.02(b)(iv) to refinance Indebtedness incurred pursuant to this Section 5.02(c) (but excluding any Additional Refinancing Amount). 

(d)    Any Subsidiary of the Company required to Guarantee the Notes pursuant to Section 5.02(a) or that chooses to
Guarantee the Notes shall (i) execute and deliver to the Trustee a supplemental indenture substantially in the Form of Exhibit B or otherwise satisfactory to the Trustee pursuant to which such Subsidiary shall unconditionally Guarantee
all of the Company’s obligations under the Notes and the Indenture in respect of the Notes on the terms set forth in the Indenture and (ii) deliver to the Trustee an 

  
 17 








 
Opinion of Counsel. The execution by each Subsidiary Guarantor of a supplemental indenture in the form of Exhibit B evidences the Note Guarantee of such Subsidiary Guarantor, whether or
not the person signing as an officer of the Subsidiary Guarantor still holds that office at the time of authentication of any Note. The delivery of any Note by the Trustee after authentication constitutes due delivery of the Note Guarantee set forth
in the Indenture on behalf of each Subsidiary Guarantor. 
 Section 5.03.    Limitation on Sale and
Leaseback. So long as any Notes are outstanding, the Company will not, and will not permit any of its Subsidiaries to, enter into any Sale and Leaseback Transaction unless: 

(i)    the Sale and Leaseback Transaction is solely with the Company or any of its Subsidiaries; 

(ii)    the lease is for a period not in excess of 24 months, including renewals; 

(iii)    the Company or such Subsidiary would (at the time of entering into such arrangement) be entitled
as described in clauses (i) through(ix) of Section 5.01(b), without equally and ratably securing the Notes then outstanding under the Indenture, to create, incur, issue, assume or guarantee Indebtedness secured by a Lien on such property or
assets in the amount of the Attributable Debt arising from such Sale and Leaseback Transaction; 

(iv)    the Company or such Subsidiary, within 360 days after the sale of property or assets in connection
with such Sale and Leaseback Transaction is completed, applies an amount equal to the greater of (A) the net proceeds of the sale of such Principal Property or (B) the fair market value of such Principal Property to (1) the retirement
of Notes, other Funded Debt of the Company ranking on a parity with the Notes or Funded Debt of a Subsidiary of the Company or (2) the purchase of property or assets used or useful in its business or to the retirement of long-term indebtedness;
or 
 (v)    the Attributable Debt of the Company and its Subsidiary in respect of such Sale and
Leaseback Transaction and all other Sale and Leaseback Transactions entered into after the Closing Date (other than any such Sale and Leaseback Transaction as would be permitted as described in clauses (i) through (iv) of Section 5.03),
plus the aggregate principal amount (without duplication) of (x) Indebtedness secured by Liens then outstanding (not including any such Indebtedness secured by Liens described in clauses (i) through (ix) of Section 5.01(b)) which do not
equally and ratably secure the Notes (or secure Notes on a basis that is prior to other Indebtedness secured thereby) and (y) Non-Guarantor Subsidiary Debt (with the exception of Non-Guarantor Subsidiary Debt which is described in clauses (i) through (vi) of Section 5.02(b)), would not exceed an amount equal to (x) 15% of Consolidated Net Tangible Assets less (y) the aggregate
principal amount of the Secured Notes outstanding at such time and the amount of (i) any Indebtedness incurred to extend, renew, replace or refund the 

  
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Secured Notes secured by Liens pursuant to Section 5.01(b)(viii), (ii) any Indebtedness incurred pursuant to Section 5.01(b)(viii) above to refinance Indebtedness incurred pursuant to Section
5.01(c) and (iii) any Indebtedness incurred pursuant to Section 5.02(b)(vi)Section 5.02(b)(iv) to refinance Indebtedness incurred pursuant to Section 5.02(c) (but excluding any Additional Refinancing Amount). 

ARTICLE 6 
 CONSOLIDATION, MERGER
OR SALE OF ASSETS 
 Section 6.01.    In General. Article 5 of the Base Indenture will apply to the Notes as
modified by Section 6.01 hereof. 
 Section 6.02.    Additional Provisions. Notwithstanding
Section 5.01 of the Base Indenture, the Company or the Parent Guarantor may transfer its property or assets to a Guarantor. 
 ARTICLE 7

 DEFAULT AND REMEDIES 

Section 7.01.    In General. Article 7 of the Base Indenture will apply to the Notes as modified by
Section 7.01 hereof. 
 Section 7.02.    Additional Provisions. Section 7.01(c) of the Base Indenture
is amended, supplemented and restated as follows: 
 “(c) the Company defaults in the performance of or breaches any other covenant or
agreement in this Indenture with respect to any Security of such series or in the Securities of such series (other than a Default specified in clause (a) and (b) above) and such default or breach continues for a period of 90 consecutive days
(or, in the case of a default in the performance of or breach of the covenant described under Section 6.03 of the Base Indenture, such default or breach continues for a period of 120 consecutive days) or more after written notice to the Company
by the Trustee or to the Company and the Trustee by the Holders of 25% or more in aggregate Principal amount of the Securities of all series affected thereby specifying such default or breach and requiring it to be remedied and stating that such
notice is a “Notice of Default” hereunder;” 
 ARTICLE 8 

SATISFACTION AND DISCHARGE; DEFEASANCE 

Section 8.01.    In General. Article 10 of the Base Indenture will apply to the Notes as modified by Article 8
hereof. 

  
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 Section 8.02.    Satisfaction and Discharge of
Indenture. (a) Section 10.01(b) of the Base Indenture is amended and supplemented by adding the following at the end of such clause:  

“provided, (i) upon any redemption that requires the payment of the Applicable Premium, the amount deposited will be
sufficient for purposes of the Indenture to the extent that an amount is deposited with the Trustee equal to the Applicable Premium calculated as of the date of the notice of redemption, with any deficit as of the applicable redemption date (the
“Applicable Premium Deficit”) only required to be deposited with the Trustee on or prior to the date of redemption and (ii) any Applicable Premium Deficit will be set forth in an Officer’s Certificate delivered to the
Trustee simultaneously with the deposit of such Applicable Premium Deficit that confirms that such Applicable Premium Deficit will be applied toward such redemption;” 

(b)    Section 10.01(c) of the Base Indenture is amended by substituting “Section 8.01” with
“Section 10.01.” 
 Section 8.03.    Defeasance and Discharge. (a) Section 10.05 of
the Base Indenture is amended, supplemented and restated as follows: 
 “The Company shall be deemed to have paid and shall be
discharged from any and all obligations in respect of the Securities, after the deposit referred to in clause (i) hereof has been made, and the provisions of the Indenture shall no longer be in effect with respect to the Securities (and the
Trustee, at the reasonable written request and expense of the Company, shall execute proper instruments acknowledging the same), except as to: (a) rights of Holders of the Securities to receive payments of Principal thereof, premium thereto,
and interest thereon, upon the original stated due dates therefor, (b) the Company’s obligations with respect to the issuance of temporary Securities and the registration of transfer with respect to the Securities, the Company’s right
of optional redemption, substitution of mutilated, defaced, destroyed, lost or stolen Securities and the maintenance an office or agency for payment for security payments held in trust pursuant to clause (i) hereof, (c) the rights, obligations
and immunities of the Trustee hereunder, and (d) the defeasance provisions contained in Article 10 of the Base Indenture; provided that the following conditions shall have been satisfied: 

(i)    with reference to Section 10.05 of the Base Indenture, the Company irrevocably has deposited or
caused to be deposited with the Trustee (or another qualifying trustee satisfying the requirements set out in the Indenture) as trust funds in trust, for the purposes of making the following payments, specifically pledged as security for, and
dedicated solely to, the benefits of the Holders of the Securities, (A) money in an amount, (B) U.S. Government Obligations that through the payment of interest and principal in respect thereof in accordance with their terms will provide
not later than one day before the due date of any payment referred to in subclause (x) or (y) of this clause (i), or (C) a combination thereof, in each case sufficient as certified by the chief financial officer of the Company in a written
certification delivered to the Trustee, to pay and discharge, without consideration of reinvestment and after payment of all federal, state and local taxes or other charges and assessments in respect thereof, and which shall be applied by the
Trustee to pay and discharge (x) all of the Principal of, premium, if any, and each installment of interest on the outstanding Securities on the maturity or due dates thereof or if the Company has made


  
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irrevocable arrangements satisfactory to the Trustee for the giving of notice of redemption by the Trustee, the redemption date, as the case may be, and (y) any mandatory sinking fund
payments or analogous payments applicable to the Securities on the day on which such payments are due and payable in accordance with the terms of Securities and the Indenture with respect to the Securities, provided, (i) upon any
redemption that requires the payment of the Applicable Premium, the amount deposited will be sufficient for purposes of the Indenture to the extent that an amount is deposited with the Trustee equal to the Applicable Premium calculated as of the
date of the notice of redemption, with any Applicable Premium Deficit only required to be deposited with the Trustee on or prior to the date of redemption and (ii) any Applicable Premium Deficit will be set forth in an Officer’s
Certificate delivered to the Trustee simultaneously with the deposit of such Applicable Premium Deficit that confirms that such Applicable Premium Deficit will be applied toward such redemption; 

(ii)    the Company has delivered to the Trustee (A) either (x) an Opinion of Counsel to the effect
that, under then applicable U.S. federal income tax law, beneficial owners of Securities will not recognize income, gain or loss for U.S. federal income tax purposes as a result of the Company’s exercise of its option under this
Section 10.05 and will be subject to U.S. federal income tax on the same amount and in the same manner and at the same times as would have been the case if such deposit, defeasance and discharge had not occurred or (y) a ruling directed to
the Trustee received from the Internal Revenue Service to the same effect as the aforementioned Opinion of Counsel and (B) an Opinion of Counsel to the effect that the creation of the defeasance trust does not violate the Investment Company Act
of 1940, as amended; 
 (iii)    immediately after giving effect to such deposit on a pro forma basis, no
Event of Default, or event that after the giving of notice or lapse of time or both would become an Event of Default other than may arise from making such deposit; 

(iv)    the Company shall have delivered to the Trustee an Officers’ Certificate and an Opinion of
Counsel, each stating that all conditions precedent to the defeasance and discharge under this Section 10.05 have been complied with; and 

(v)    if the Securities are to be redeemed prior to the final maturity thereof (other than from mandatory
sinking fund payments or analogous payments), notice of such redemption shall have been duly given pursuant to the Indenture or provision therefor satisfactory to the Trustee shall have been made.” 

Section 8.04.    Defeasance of Certain Obligations. (a) Notwithstanding anything to the contrary in
Section 10.06 of the Base Indenture and in addition to the covenants, terms, provisions or conditions specified therein, the Company may omit to comply with any term, provision or condition set forth in, and the Indenture will no longer be in
effect with respect to, Section 4.01, Section 5.01 through Section 5.03 and Article 6 of this 

  
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Seventh Supplemental Indenture and Section 4.05, Article 5, Section 6.03 and clauses (c) and (h) of Section 7.01 of the Base Indenture, provided the conditions set forth in
clauses (a) through (f) of Section 10.06 of the Base Indenture, as modified by Section 8.04(b) hereto, have been satisfied. 

(b)    Section 10.06(a) of the Base Indenture is amended and supplemented by adding the following at the end of such
clause: 
 “provided, (i) upon any redemption that requires the payment of the Applicable Premium, the amount deposited
will be sufficient for purposes of the Indenture to the extent that an amount is deposited with the Trustee equal to the Applicable Premium calculated as of the date of the notice of redemption, with any Applicable Premium Deficit only required to
be deposited with the Trustee on or prior to the date of redemption and (ii) any Applicable Premium Deficit will be set forth in an Officer’s Certificate delivered to the Trustee simultaneously with the deposit of such Applicable Premium
Deficit that confirms that such Applicable Premium Deficit will be applied toward such redemption;” 
 ARTICLE 9 

AMENDMENTS, SUPPLEMENTS AND WAIVERS 

Section 9.01.    In General. Article 11 of the Base Indenture will apply to the Notes as modified by this
Article 9. 
 Section 9.02.    Without Consent of Holders. In addition to the provisions listed in
Section 11.01 of the Base Indenture, the Company and the Trustee may amend or supplement the Indenture or the Notes without notice to or consent of any Holder to provide for any Guarantee of the Notes, to secure the Notes or any Guarantee of
the Notes or to confirm and evidence the release, termination or discharge of any Guarantee of the Notes or any security therefor when such release, termination or discharge is permitted by the Indenture. 

Section 9.03.    With Consent of Holders. In addition to the provisions listed in Section 11.02 of
the Base Indenture, without the consent of each Holder of the Notes affected thereby, an amendment or waiver may not: 

(a)    change the optional redemption dates or optional redemption prices of the Notes from those stated under
“Optional Redemption” on the reverse of each Note; 
 (b)    amend, change or modify the obligation of the
Company to make and consummate an Offer to Purchase under Article 4 after a Change of Control Repurchase Event has occurred, including, in each case, amending, changing or modifying any definition relating thereto; or 

(c)    modify or change any provision of the Indenture affecting the ranking of the Notes or any Note Guarantee in a
manner adverse to any Holder. 

  
 22 








 ARTICLE 10 

GUARANTEES 

Section 10.01.    In General. Article 12 of the Base Indenture will apply to the Notes. 

Section 10.02.    Additional Provisions. Each Guaranteeing Subsidiary hereby agrees to become a party to the
Indenture as a Subsidiary Guarantor and shall have all of the rights and be subject to all of the obligations and agreements of a Subsidiary Guarantor under the Indenture. Each Guaranteeing Subsidiary agrees to be bound by all of the provisions of
the Indenture applicable to a Subsidiary Guarantor and to perform all of the obligations and agreements as follows: 

(a)    Subject to the provisions of this Seventh Supplemental Indenture, each Guaranteeing Subsidiary hereby irrevocably
and unconditionally Guarantees on an unsecured unsubordinated basis, the full and punctual payment (whether at stated maturity, upon redemption, purchase pursuant to an offer to purchase or acceleration, or otherwise) of the Principal of, interest
on and all other amounts payable under, the Notes, and the full and punctual payment of all other amounts payable by the Company under this Seventh Supplemental Indenture in respect of the Notes. Upon failure by the Company to pay punctually any
such amount, each Guarantor shall forthwith on demand pay the amount not so paid at the place and in the manner specified in the Indenture. 

(b)    The obligations of each Guaranteeing Subsidiary hereunder are unconditional and absolute and, without limiting the
generality of the foregoing, will not be released, discharged or otherwise affected by: 
 (i)    any
extension, renewal, settlement, compromise, waiver or release in respect of any obligation of the Company under the Indenture or the Notes, by operation of law or otherwise; 

(ii)    any modification or amendment of or supplement to the Indenture or the Notes; 

(iii)    any change in the corporate existence, structure or ownership of the Company, or any insolvency,
bankruptcy, reorganization or other similar proceeding affecting the Company or its assets or any resulting release or discharge of any obligation of the Company contained in the Indenture or the Notes; 

(iv)    the existence of any claim, set-off or other rights which
such Guaranteeing Subsidiary may have at any time against the Company, the Trustee or any other Person, whether in connection with the Indenture or any unrelated transactions, provided that nothing herein prevents the assertion of any such
claim by separate suit or compulsory counterclaim; 

  
 23 








 (v)    any invalidity or unenforceability relating to or
against the Company for any reason of the Indenture or the Notes, or any provision of applicable law or regulation purporting to prohibit the payment by the Company of the Principal of or interest on the Notes or any other amount payable by the
Company under the Indenture; or 
 (vi)    any other act or omission to act or delay of any kind by the
Company, the Trustee or any other Person or any other circumstance whatsoever which might, but for the provisions of this paragraph, constitute a legal or equitable discharge of or defense to such Guaranteeing Subsidiary’s obligations
hereunder. 
 (c)    Except as otherwise provided in the Indenture, each Guaranteeing Subsidiary’s obligations
hereunder will remain in full force and effect until the Principal of and interest on the Notes and all other amounts payable by the Company under the Indenture have been paid in full. If at any time any payment of the Principal of or interest on
the Notes or any other amount payable by the Company under the Indenture is rescinded or must be otherwise restored or returned upon the insolvency, bankruptcy or reorganization of the Company or otherwise, each Guaranteeing Subsidiary’s
obligations hereunder with respect to such payment will be reinstated as though such payment had been due but not made at such time. 

(d)    Each Guaranteeing Subsidiary irrevocably waives acceptance hereof, presentment, demand, protest and any notice not
provided for herein, as well as any requirement that at any time any action be taken by any Person against the Company or any other Person. 

(e)    Upon making any payment with respect to any obligation of the Company under this Article, each Guaranteeing
Subsidiary making such payment will be subrogated to the rights of the payee against the Company with respect to such obligation, provided that such Guaranteeing Subsidiary may not enforce either any right of subrogation, or any right to
receive payment in the nature of contribution, or otherwise, from any other Guarantor, with respect to such payment so long as any amount payable by the Company hereunder or under the Notes remains unpaid. 

(f)    If acceleration of the time for payment of any amount payable by the Company under the Indenture in respect of the
Notes or the Notes is stayed upon the insolvency, bankruptcy or reorganization of the Company, all such amounts otherwise subject to acceleration under the terms of the Indenture in respect of the Notes are nonetheless payable by the Guaranteeing
Subsidiaries hereunder forthwith on demand by the Trustee or the Holders of the Notes. 
 (g)    Notwithstanding
anything to the contrary in this Seventh Supplemental Indenture, each Guaranteeing Subsidiary, and by its acceptance of Notes, each Holder, confirms that it is the intention of all such parties that the Note Guarantee of such Guaranteeing Subsidiary
not constitute a fraudulent conveyance under applicable fraudulent conveyance provisions of the United States Bankruptcy Code or any 

  
 24 








 
comparable provision of state law. To effectuate that intention, the Trustee, the Holders of the Notes and each Guaranteeing Subsidiary irrevocably agree that the obligations of each Guaranteeing
Subsidiary under its Note Guarantee are limited to the maximum amount that would not render such Guaranteeing Subsidiary’s obligations subject to avoidance under applicable fraudulent conveyance provisions of the United States Bankruptcy Code
or any comparable provision of state law. 
 (h)    The Note Guarantee of a Subsidiary Guarantor will terminate upon:

 (i)    the release or discharge (other than a discharge through payment thereon) of the Indebtedness
of such Subsidiary that resulted in the obligation to Guarantee the Notes pursuant to Section 5.02(a) (or, in respect of the Subsidiary Guarantors on the Closing Date, release of their guarantees of all other Indebtedness of the Company); 

(ii)    a sale or other disposition (including by way of consolidation or merger) of the Capital Stock of
the Subsidiary such that the Subsidiary is no longer a Subsidiary of the Parent Guarantor; 

(iii)    defeasance or discharge of the Notes, as provided under Article 10 of the Base Indenture and
Article 8 hereof; or 
 (iv)    if such Subsidiary Guarantor was not required to Guarantee the Notes
pursuant to Section 5.02(a) but did so at its option, then if it requests such release at any time; provided that after giving effect to such release the Company would be in compliance with the covenant set forth in this Section 10.02.

 Upon delivery by the Company to the Trustee of an Officers’ Certificate and an Opinion of Counsel, the Trustee will execute any
documents reasonably required in order to evidence the release of the Subsidiary Guarantor from its obligations under its Note Guarantee. 

ARTICLE 11 
 MISCELLANEOUS 

Section 11.01.    Trust Indenture Act of 1939. This Seventh Supplemental Indenture shall incorporate and be
governed by the provisions of the Trust Indenture Act that are required to be part of and to govern indentures qualified under the Trust Indenture Act. 

Section 11.02.    Governing Law. The laws of the State of New York shall govern this Seventh Supplemental
Indenture and the Notes. 
 Section 11.03.    Duplicate Originals. The parties may sign any number of copies
of this Seventh Supplemental Indenture. Each signed copy shall be an original, but all of them together represent the same agreement. 

Section 11.04.    Separability. In case any provision in this Seventh Supplemental Indenture or the Notes
shall be invalid, illegal or unenforceable, the validity, legality and enforceability of the remaining provisions shall not in any way be affected or impaired thereby. 

  
 25 








 Section 11.05.    Ratification. The Base Indenture, as
supplemented and amended by the Fourth Supplemental Indenture, the Sixth Supplemental Indenture and this Seventh Supplemental Indenture, is in all respects ratified and confirmed. The Base Indenture and the Fourth Supplemental Indenture, the Sixth
Supplemental Indenture and this Seventh Supplemental Indenture shall be read, taken and construed as one and the same instrument. All provisions included in this Seventh Supplemental Indenture supersede any conflicting provisions included in the
Base Indenture unless not permitted by law. The Trustee accepts the trusts created by the Base Indenture, as supplemented by the Fourth Supplemental Indenture, the Sixth Supplemental Indenture and this Seventh Supplemental Indenture, and agrees to
perform the same upon the terms and conditions of the Base Indenture, as supplemented by the Fourth Supplemental Indenture, the Sixth Supplemental Indenture and this Seventh Supplemental Indenture. 

Section 11.06.    Effectiveness. The provisions of this Seventh Supplemental Indenture shall become effective
as of the date hereof. 
 Section 11.07.    Successors. All agreements of the Company and the Parent
Guarantor in this Seventh Supplemental Indenture shall bind their successors. All agreements of the Trustee in this Seventh Supplemental Indenture shall bind its successors. 

Section 11.08.    Trustee’s Disclaimer. The recitals contained herein shall be taken as the
statements of the Company and the Parent Guarantor and the Trustee assumes no responsibility for their correctness. The Trustee shall not be responsible in any manner whatsoever for or in respect of the validity or sufficiency of this Seventh
Supplemental Indenture, the Notes, any Guarantee or for or in respect of the recitals contained herein, all of which recitals are made solely by the Company and the Parent Guarantor. 

[Remainder of page intentionally left blank.] 

  
 26 








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

					
	 AK STEEL CORPORATION
 as the
Company

		
	By:	 	 /s/ Joseph C. Alter

		 	Name:	 	Joseph C. Alter
		 	Title:	 	Vice President, General Counsel and Corporate Secretary
	
	 AK STEEL HOLDING CORPORATION
 as
Parent Guarantor

		
	By:	 	 /s/ Joseph C. Alter

		 	Name:	 	Joseph C. Alter
		 	Title:	 	Vice President, General Counsel and Corporate Secretary
	
	 AK STEEL PROPERTIES, INC.
 as
Guarantor

		
	By:	 	 /s/ Amy K. Dornacher

		 	Name:	 	Amy K. Dornacher
		 	Title:	 	Secretary
	
	 AK TUBE LLC
 as
Guarantor

		
	By:	 	 /s/ Amy K. Dornacher

		 	Name:	 	Amy K. Dornacher
		 	Title:	 	Secretary
	
	 MOUNTAIN STATE CARBON, LLC
 as
Guarantor

		
	By:	 	 /s/ Lawrence R. Hermes

		 	Name:	 	Lawrence R. Hermes
		 	Title:	 	Vice President and Chief Financial Officer


 [Signature Page to Seventh Supplemental Indenture]









					
	 U.S. BANK NATIONAL ASSOCIATION,
 as
Trustee

		
	By:	 	 /s/ William E. Sicking

		 	Name:	 	William E. Sicking
		 	Title:	 	Vice President & Trust Officer









 EXHIBIT A 

[UNLESS THIS CERTIFICATE IS PRESENTED BY AN AUTHORIZED REPRESENTATIVE OF THE DEPOSITORY TRUST COMPANY, TO THE COMPANY OR ITS AGENT FOR
REGISTRATION OF TRANSFER, EXCHANGE OR PAYMENT, AND ANY CERTIFICATE ISSUED IN EXCHANGE FOR THIS CERTIFICATE OR ANY PORTION HEREOF IS REGISTERED IN THE NAME OF CEDE & CO. OR IN SUCH OTHER NAME AS IS REQUESTED BY AN AUTHORIZED REPRESENTATIVE
OF THE DEPOSITORY TRUST COMPANY OR SUCH OTHER REPRESENTATIVE OF THE DEPOSITORY TRUST COMPANY OR SUCH OTHER NAME AS IS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF THE DEPOSITORY TRUST COMPANY (AND ANY PAYMENT HEREON IS MADE TO CEDE & CO.),
ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON OTHER THAN THE DEPOSITORY TRUST COMPANY OR CEDE & CO. IS WRONGFUL INASMUCH AS THE REGISTERED OWNER HEREOF, CEDE & CO., HAS AN INTEREST HEREIN.]

 [THIS NOTE IS A GLOBAL SECURITY AND IS REGISTERED IN THE NAME OF A DEPOSITORY OR A NOMINEE THEREOF. TRANSFERS OF THIS GLOBAL NOTE SHALL
BE LIMITED TO TRANSFERS IN WHOLE, BUT NOT IN PART, TO NOMINEES OF THE DEPOSITORY TRUST COMPANY OR TO A SUCCESSOR THEREOF OR SUCH SUCCESSOR’S NOMINEE AND TRANSFERS OF PORTIONS OF THIS GLOBAL NOTE SHALL BE LIMITED TO TRANSFERS MADE IN ACCORDANCE
WITH THE RESTRICTIONS SET FORTH IN THE INDENTURE REFERRED TO ON THE REVERSE HEREOF.] 
 7.00% Senior Note due 2027 

AK STEEL CORPORATION 
  

			
		  	CUSIP: 001546 AU4
		  	ISIN: US001546AU45
	No. 001	  	$400,000,000

 AK STEEL CORPORATION, a corporation duly organized and existing under the laws of the State of Delaware
(herein called the “Company,” which term includes any successor corporation under the Indenture hereinafter referred to on the reverse hereof), for value received, promises to pay to CEDE & CO., or its registered assigns,
the Principal sum of FOUR HUNDRED MILLION DOLLARS ($400,000,000) or such other amount as indicated on the Schedule of Increases and Decreases attached hereto on March 15, 2027. 

Interest Rate: 7.00% per year 

Interest Payment Dates: March 15 and September 15 of each year, commencing September 15, 2017 

  
 A-1 








 Record Dates: March 1 and September 1 

Reference is hereby made to the further provisions of this Note set forth on the reverse hereof, which will for all purposes have the same
effect as if set forth at this place. 
 Unless the certificate of authentication hereon has been executed by the Trustee referred to on the
reverse hereof, directly or through an Authenticating Agent, by the manual or facsimile signature of an authorized Officer, this Note shall not be entitled to any benefit under the Indenture or be valid or obligatory for any purpose. 

  
 A-2 








 IN WITNESS WHEREOF, the Company has caused this instrument to be duly executed. 

Dated: March 23, 2017 
  

			
	AK STEEL CORPORATION
		
	By:	 	  

		 	Name:
		 	Title:



  
 A-3 








 TRUSTEE’S CERTIFICATE OF AUTHENTICATION 

This is one of the Notes of the series designated therein referred to in the within-mentioned Indenture. 

Dated: March 23, 2017 
  

			
	 U.S. BANK NATIONAL ASSOCIATION
 as
the Trustee

		
	By:	 	  

		 	Name:
		 	Title:



  
 A-4 








 [REVERSE OF NOTE] 

7.00% SENIOR NOTE DUE 2027 

Indenture. This Note is one of the 7.00% Senior Notes due 2027 (the “Notes”) of the Company issued under an Indenture,
dated as of May 11, 2010 (the “Base Indenture”), between the Company, AK Holding Corporation (the “Parent Guarantor”) and U.S. Bank National Association, as Trustee (herein called the
“Trustee,” which term includes any successor trustee under the Indenture), as supplemented by the Fourth Supplemental Indenture dated April 29, 2014 (the “Fourth Supplemental Indenture”), the Sixth Supplemental
Indenture dated July 27, 2016 (the “Sixth Supplemental Indenture”), the Seventh Supplemental Indenture dated March 23, 2017 (the “Seventh Supplemental Indenture” and, together with the Base Indenture, the
Fourth Supplemental Indenture and the Sixth Supplemental Indenture, the “Indenture”), to which Indenture and all indentures supplemental thereto reference is hereby made for a statement of the respective rights, limitations of
rights, duties and immunities thereunder of the Company, the Parent Guarantor, AK Tube LLC (“AK Tube”), AK Steel Properties, Inc. (“AK Steel Properties”) and Mountain State Carbon, LLC (“MSC,” and
together with AK Tube and AK Steel Properties, each a “Subsidiary Guarantor” and together the “Subsidiary Guarantors”), as guarantors, the Trustee and the Holders of the Notes and of the terms upon which the Notes
are, and are to be, authenticated and delivered. To the extent that the terms of the Indenture and this Note are inconsistent, the terms of the Indenture shall govern. The aggregate principal amount of the Notes that may be authenticated and
delivered under the Indenture, as amended hereby, shall be $400,000,000 on the Closing Date. The Company may, without notice to or the consent of the Holders, create and issue additional Securities having the same terms as, and ranking equally and
ratably with, the Notes in all respects and so that such additional Notes will be consolidated and form a single series with, and have the same terms as to status, redemption or otherwise as, the Notes initially issued; provided that if the
additional Securities are not fungible with the Notes for U.S. federal income tax purposes, the additional Securities will have a separate CUSIP number. 

Interest. The Company promises to pay interest on the principal amount of the Notes at the rate per year described above. Interest on
the Notes will accrue from March 23, 2017. Interest on the Notes will be payable semi-annually on March 15 and September 15 of each year, beginning September 15, 2017. The interest so payable and punctually paid or duly provided
for, on any interest payment date, will be paid to the Person in whose names the Notes are registered at the close of business on the record date for such interest, which shall be the March 1 or September 1, as the case may be, preceding such
interest payment date, except that interest payable at maturity will be paid to the same Persons to whom Principal of the Notes is payable. Interest will be computed on the basis of a 360- day year consisting
of twelve 30-day months. The interest period relating to an interest payment date (including the maturity date) shall be the period from, and including, the most recent preceding interest payment date (or, in
the case of the first interest period, March 23, 2017) to, but excluding, the relevant interest payment date. 

  
 A-5 








 All payments on the Notes, including Principal of, premium, if any, and interest on, will be
payable at the Corporate Trust Office of the Trustee, as Paying Agent under the Indenture as set forth in the Indenture. 
 If any interest
payment date, maturity date or redemption date of a Note falls on a day that is not a Business Day, the required payment of Principal and interest may be made on the next succeeding Business Day as if made on the date that the payment was due and no
interest will accrue on that payment for the period from and after that interest payment date, maturity date or redemption date, as the case may be, to the date of that payment on the next succeeding Business Day. 

Sinking Fund. The Notes will not be subject to any sinking fund. 

Optional Redemption. (a) At any time prior to March 15, 2022, the Company may redeem the Notes at its option, in whole at any
time or in part, at a redemption price equal to 100% of the principal amount of the Notes to be redeemed plus the Applicable Premium, plus accrued and unpaid interest to the redemption date. 

For the purposes of the preceding paragraph, the following terms shall have the following definitions: 

“Applicable Premium” means, with respect to any Note on any redemption date, the greater of 

(1)    1.0% of the principal amount of such Note, and 

(2)    the excess, if any of 

(a)    the present value at such redemption date of (i) the redemption price of such Note at March 15, 2022 (as
set forth in the table below), plus (ii) all required interest payments due on such Note through March 15, 2022 (excluding accrued and unpaid interest to the redemption date), computed using a discount rate equal to the Treasury Rate as of
such redemption date plus 50 basis points; over 
 (b)    the then outstanding principal amount of such Note. 

“Treasury Rate” means, as of any redemption date, the yield to maturity as of such redemption date of United States Treasury
securities with a constant maturity (as compiled and published in the most recent Federal Reserve Statistical Release H.15(519) that has become publicly available at least two business days prior to the redemption date (or, if such Statistical
Release is no longer published, any publicly available source of similar market data)) most nearly equal to the period from the redemption date to March 15, 2022; provided, however, that if the period from the redemption date to
March 15, 2022, is less than one year, the weekly average yield on actually traded United States Treasury securities adjusted to a constant maturity of one year will be used. 

(b)    At any time on or after March 15, 2022, the Company may redeem the Notes, in whole or in part, at the
redemption price for the Notes (expressed as a 

  
 A-6 








 
percentage of principal amount) set forth below, plus accrued and unpaid interest to the redemption date, if redeemed during the twelve-month period commencing on March 15 of the years
indicated below: 
  

					
	Year	  	Redemption Price	 
	 2022
	  	 	103.500	% 
	 2023
	  	 	102.333	% 
	 2024
	  	 	101.167	% 
	 2025 and thereafter
	  	 	100.000	% 

 (c)    At any time prior to March 15, 2020, the Company may redeem up to 35% of the
principal amount of the Notes (including any additional Notes) with the net cash proceeds of one or more sales of the Parent Guarantor’s common stock (to the extent proceeds are contributed to the Company as equity) at a redemption price
(expressed as a percentage of principal amount) of 107.000%, plus accrued and unpaid interest to the redemption date; provided that at least 65% of the aggregate principal amount of Notes originally issued on the Closing Date remains
outstanding after each such redemption and notice of any such redemption is mailed within 60 days of each such sale of common stock. 

(d)    No Note of $2,000 principal amount or less shall be redeemed in part. If any Note is to be redeemed in part only,
the notice of redemption relating to such Note will state the portion of the principal amount to be redeemed. A new Note in principal amount equal to the unredeemed portion will be issued upon cancellation of the original Note. 

Events of Default. If an Event of Default with respect to Notes of this series shall occur and be continuing, the Principal of the
Notes of this series may be declared due and payable in the manner and with the effect provided in the Indenture. 
 The Guarantees.
The Notes are fully and unconditionally guaranteed by the Parent Guarantor and each Subsidiary Guarantor, if any. 
 Amendment;
Waiver. The Indenture provides that the Company, the Parent Guarantor and the Trustee may take certain actions to amend the Indenture or the Notes without notice to or the consent of any Holder of Notes. In addition, the Indenture permits, with
certain exceptions as therein provided, the Company, the Parent Guarantor and the Trustee to otherwise amend the Indenture or the Notes with the consent of the Holders of a majority in principal amount of the Notes affected by such amendment.
However, certain actions of the Company require the consent of each Holder of outstanding Notes affected thereby. 
 The Company may elect
in any particular instance not to comply with certain covenants set forth in the Indenture or the Notes if, before the time for such compliance, the Holders of a majority in principal amount of the Notes either waive compliance in that instance or
generally waive compliance with those provisions, but the waiver may not extend to or affect any term, provision or condition except to the extent expressly so waived, and, until the waiver becomes effective, the Company’s obligations and the
duties of the Trustee in respect of any such provision will remain in full force and effect. 

  
 A-7 








 Payments. No reference herein to the Indenture and no provision of this Note or of the
Indenture shall alter or impair the obligation of the Company, which is absolute and unconditional, to pay the Principal of (and premium, if any) and interest on this Note at the times, place and rate, and in the coin or currency, herein prescribed.

 Registered Form. The Notes will be issued in fully registered form only in minimum denominations of $2,000 and integral multiples
of $1,000 in excess thereof. 
 Choice of Law. This Note shall be governed by, and construed in accordance with, the laws of the
State of New York. 
 Defined Terms. All terms used in this Note which are defined in the Indenture shall have the meanings assigned
to them in the Indenture. 

  
 A-8 








 ABBREVIATIONS 

The following abbreviations, when used in the inscription on the face of this instrument, shall be construed as though they were written out
in full according to applicable laws or regulations. 
 TEN COM - as tenants in common 

TEN ENT - as tenants by the entireties 

JT TEN - as joint tenants with right of survivorship and not as tenants in common 

UNIF GIFT MIN ACT -             Custodian 

 

	
	 (Cust)

(Minor)

Under Uniform Gifts to Minors Act

	
	 (State)



 Additional abbreviations may also be used though not in the above list. 

  
 A-9 








 ASSIGNMENT 

FOR VALUE RECEIVED, the undersigned hereby sell(s), assign(s) and transfer(s) unto
                     PLEASE INSERT SOCIAL SECURITY NUMBER OR OTHER IDENTIFYING NUMBER OF ASSIGNEE 

(Please print or type name and address, including postal zip code, of assignee) the within Note and all rights thereunder, hereby irrevocably
constitutes and appoints 
 to transfer said Note on the books of the Company, with full power of substitution in the premises. 

Dated:                      

NOTICE: The signature to this assignment must correspond with the name as written upon the face of the within instrument in every particular, without
alteration or enlargement or any change whatsoever. 

  
 A-10 








 OPTION OF HOLDER TO ELECT PURCHASE 

If you wish to have this Note purchased by the Company pursuant to Article 4 of the Seventh Supplemental Indenture, check the
Box:  ☐ 
 If you wish to have a portion of this Note purchased by the Company pursuant to Article 4 of the Seventh
Supplemental Indenture, state the principal amount: $        . 
 Date: 

Your Signature: 
 (Sign exactly as your name appears on the
other side of this Note) 
 Signature Guarantee: 
 Signature
must be guaranteed by a participant in a recognized signature guaranty medallion program or other signature guarantor acceptable to the Trustee. 

  
 A-11 








 Schedule I 

[Include Schedule I only for a Global Note] 

SCHEDULE OF INCREASES OR DECREASES 
 The
initial principal amount of this Global Note is $400,000,000. The following increases or decreases in the Principal amount of this Global Note have been made: 
  

																	
	Date	  	 Amount of

decrease in

Principal Amount

of this Global Note
	 	  	 Amount of

increase in
 Principal Amount

of this Global Note
	 	  	 Principal Amount

of this Global Note

following such
 increase or

decrease
	 	  	 Signature of

authorized
 signatory of

Trustee
	 
		  				  				  				  			
		  				  				  				  			
		  				  				  				  			


  
 A-12 








 EXHIBIT B 

FORM OF SUPPLEMENTAL INDENTURE 

TO BE DELIVERED BY SUBSIDIARY GUARANTORS 

SUPPLEMENTAL INDENTURE (this “Supplemental Indenture”), dated as of
                    , among                     
(the “Guaranteeing Subsidiary”), a subsidiary of                      (or its permitted successor), AK Steel Corporation (the
“Company”), a corporation organized under the laws of Delaware, AK Steel Holding Corporation, a Delaware corporation (the “Parent Guarantor”) and U.S. Bank National Association, as trustee under the Indenture
referred to below (the “Trustee”). 
 W I T N E S S E T H 

WHEREAS, the Company, the Parent Guarantor and the Trustee executed and delivered an Indenture, dated as of May 11, 2010 (the
“Base Indenture” and as supplemented by the Seventh Supplemental Indenture dated March 23, 2017 (the “Seventh Supplemental Indenture”) among the Company, the Parent Guarantor, AK Tube LLC (“AK
Tube”), AK Steel Properties, Inc. (“AK Steel Properties”) and Mountain State Carbon, LLC (“MSC,” and together with AK Tube and AK Steel Properties, each a “Subsidiary Guarantor” and
together the “Subsidiary Guarantors”), as guarantors, and the Trustee, the “Indenture”), to provide for the issuance by the Company of $400,000,000 aggregate Principal amount of the Securities of the Company
designated as its 7.00% Senior Notes due 2027; 
 WHEREAS, the Indenture provides that under certain circumstances a Subsidiary shall
execute and deliver to the Trustee a supplemental indenture pursuant to which the Subsidiary shall unconditionally Guarantee all of the Company’s obligations under the Notes and the Indenture on the terms and conditions set forth herein; and

 WHEREAS, pursuant to Section 11.01 of the Base Indenture and Section 9.02 of the Seventh Supplemental Indenture, the
Trustee is authorized to execute and deliver this Supplemental Indenture. 
 NOW THEREFORE, in consideration of the foregoing and for
other good and valuable consideration, the receipt of which is hereby acknowledged, the Guaranteeing Subsidiary, the Company, the Parent Guarantor and the Trustee mutually covenant and agree for the equal and ratable benefit of Holders as follows:

 1.    Capitalized Terms. Capitalized terms used herein without definition shall have the meanings assigned to
them in the Indenture. 
 2.    Guarantee. The Guaranteeing Subsidiary hereby agrees to become a party to the
Indenture as a Subsidiary Guarantor and shall have all of the rights and be subject to all of the obligations and agreements of a Subsidiary Guarantor under the Indenture. The Guaranteeing Subsidiary agrees to be bound by all of the provisions of
the Indenture 

  
 B-1 








 
applicable to a Subsidiary Guarantor and to perform all of the obligations and agreements as follows: 

(a)    Subject to the provisions of this Supplemental Indenture, the Guaranteeing Subsidiary hereby irrevocably and
unconditionally Guarantees on an unsecured unsubordinated basis, the full and punctual payment (whether at stated maturity, upon redemption, purchase pursuant to an offer to purchase or acceleration, or otherwise) of the Principal of, interest on
and all other amounts payable under, each Note, and the full and punctual payment of all other amounts payable by the Company under the Indenture in respect of the Notes. Upon failure by the Company to pay punctually any such amount, each Guarantor
shall forthwith on demand pay the amount not so paid at the place and in the manner specified in the Indenture. 

(b)    The obligations of each Guaranteeing Subsidiary hereunder are unconditional and absolute and, without limiting the
generality of the foregoing, will not be released, discharged or otherwise affected by: 
 i.    any
extension, renewal, settlement, compromise, waiver or release in respect of any obligation of the Company under the Indenture or any Note, by operation of law or otherwise; 

ii.    any modification or amendment of or supplement to the Indenture or any Note; 

iii.    any change in the corporate existence, structure or ownership of the Company, or any insolvency,
bankruptcy, reorganization or other similar proceeding affecting the Company or its assets or any resulting release or discharge of any obligation of the Company contained in the Indenture or any Note; 

iv.    the existence of any claim, set-off or other rights which
the Guaranteeing Subsidiary may have at any time against the Company, the Trustee or any other Person, whether in connection with the Indenture or any unrelated transactions, provided that nothing herein prevents the assertion of any such
claim by separate suit or compulsory counterclaim; 
 v.    any invalidity or unenforceability relating
to or against the Company for any reason of the Indenture or any Note, or any provision of applicable law or regulation purporting to prohibit the payment by the Company of the Principal of or interest on any Note or any other amount payable by the
Company under the Indenture; or 
 vi.    any other act or omission to act or delay of any kind by the
Company, the Trustee or any other Person or any other circumstance whatsoever which might, but for the provisions of this paragraph, constitute a legal or equitable discharge of or defense to such Guaranteeing Subsidiary’s obligations
hereunder. 

  
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 (c)    Except as otherwise provided in the Indenture, each Guaranteeing
Subsidiary’s obligations hereunder will remain in full force and effect until the Principal of and interest on the Notes and all other amounts payable by the Company under the Indenture have been paid in full. If at any time any payment of the
Principal of or interest on any Note or any other amount payable by the Company under the Indenture is rescinded or must be otherwise restored or returned upon the insolvency, bankruptcy or reorganization of the Company or otherwise, each
Guaranteeing Subsidiary’s obligations hereunder with respect to such payment will be reinstated as though such payment had been due but not made at such time. 

(d)    Each Guaranteeing Subsidiary irrevocably waives acceptance hereof, presentment, demand, protest and any notice not
provided for herein, as well as any requirement that at any time any action be taken by any Person against the Company or any other Person. 

(e)    Upon making any payment with respect to any obligation of the Company under this Article, the Guaranteeing
Subsidiary making such payment will be subrogated to the rights of the payee against the Company with respect to such obligation, provided that the Guaranteeing Subsidiary may not enforce either any right of subrogation, or any right to
receive payment in the nature of contribution, or otherwise, from any other Guarantor, with respect to such payment so long as any amount payable by the Company hereunder or under the Notes remains unpaid. 

(f)    If acceleration of the time for payment of any amount payable by the Company under the Indenture or the Notes is
stayed upon the insolvency, bankruptcy or reorganization of the Company, all such amounts otherwise subject to acceleration under the terms of the Indenture are nonetheless payable by the Guaranteeing Subsidiary hereunder forthwith on demand by the
Trustee or the Holders. 
 (g)    Notwithstanding anything to the contrary in this Supplemental Indenture, each
Guaranteeing Subsidiary, and by its acceptance of Notes, each Holder, confirms that it is the intention of all such parties that the Note Guarantee of such Guaranteeing Subsidiary not constitute a fraudulent conveyance under applicable fraudulent
conveyance provisions of the United States Bankruptcy Code or any comparable provision of state law. To effectuate that intention, the Trustee, the Holders and each Guaranteeing Subsidiary irrevocably agree that the obligations of each Guaranteeing
Subsidiary under its Note Guarantee are limited to the maximum amount that would not render the Guaranteeing Subsidiary’s obligations subject to avoidance under applicable fraudulent conveyance provisions of the United States Bankruptcy Code or
any comparable provision of state law. 
 3.    Notation not Required. Neither the Company nor the Guaranteeing
Subsidiary shall be required to make a notation on the Securities to reflect the Note Guarantee or any release, termination or discharge thereof. 

4.    Governing Law. The laws of the State of New York shall govern this Supplemental Indenture. 

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

6.    Effect of Headings. The Section headings herein are for convenience only and shall not affect the
construction hereof. 
 7.    The Trustee. The Trustee shall not be responsible in any manner whatsoever for or
in respect of the validity or sufficiency of this Supplemental Indenture or for or in respect of the recitals contained herein, all of which recitals are made solely by the Guaranteeing Subsidiary, the Company and the Parent Guarantor. 

8.    Successors. All agreements of the Guaranteeing Subsidiary in the Indenture, this Supplemental Indenture and
the Note Guarantee shall bind its successors. All agreements of the Trustee in this Supplemental Indenture shall bind its successors. 

9.    No Waiver. Neither a failure nor a delay on the part of either the Trustee or the Holders in exercising any
right, power or privilege under this Supplemental Indenture shall operate as a waiver thereof, nor shall a single or partial exercise thereof preclude any other or further exercise of any right, power or privilege. The rights, remedies and benefits
of the Trustee and the Holders herein expressly specified are cumulative and are not exclusive of any other rights, remedies or benefits which either may have under this Supplemental Indenture at law, in equity, by statute or otherwise. 

10.    Modification. No modification, amendment or waiver of any provision of this Supplemental Indenture, nor the
consent to any departure by the Guaranteeing Subsidiary therefrom, shall in any event be effective unless the same shall be in writing and signed by the Trustee, and then such waiver or consent shall be effective only in the specific instance and
for the purpose for which given. No notice to or demand on the Guaranteeing Subsidiary in any case shall entitle the Guaranteeing Subsidiary to any other or further notice or demand in the same, similar or other circumstance. 

  
 B-4 








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

			
	[Name of Guaranteeing Subsidiary], as the Guaranteeing Subsidiary
		
	By:	 	  

		 	Name:
		 	Title:
	
	 U.S. BANK NATIONAL ASSOCIATION
 as
the Trustee

		
	By:	 	  

		 	Name:
		 	Title:
	
	 AK STEEL CORPORATION
 as the
Company

		
	By:	 	  

		 	Name:
		 	Title:
	
	 AK STEEL HOLDING CORPORATION
 as the
Parent Guarantor

		
	By:	 	  

		 	Name:
		 	Title:



  
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