EXHIBIT
4.6.3





SECOND SUPPLEMENTAL INDENTURE dated as
of February 11, 2009 (this “Supplemental
Indenture”), among Barzel Industries Inc., a Delaware corporation (the
“Additional Subsidiary
Guarantor”), a direct wholly-owned subsidiary of Novamerican Steel Inc.
f/k/a Symmetry Holdings Inc., a Delaware corporation (“Novamerican”),
Novamerican Steel Finco Inc., a Delaware corporation (the “Company”),
Novamerican, the other Subsidiary Guarantors (as defined in the Indenture
referred to herein) and The Bank of New York Mellon f/k/a The Bank of New York,
as Trustee under the Indenture (the “Trustee”).




W I T N E
S S E T H:




WHEREAS, Novamerican, the Company and
the Subsidiary Guarantors party thereto have heretofore executed and delivered
to the Trustee an indenture dated as of November 15, 2007, as amended by the
First Supplemental Indenture dated as of December 3, 2007 (as so amended, the
“Indenture”),
providing for the issuance of an aggregate principal amount of $315,000,000 of
11.5% Senior Secured Notes due 2015 (the “Notes”);




WHEREAS, in its discretion, Novamerican
may have the Additional Subsidiary Guarantor, and Section 4.13 of the Indenture
provides that under certain circumstances Novamerican shall cause the Additional
Subsidiary Guarantor to, execute and deliver to the Trustee a Guaranty Agreement
pursuant to which the Additional Subsidiary Guarantor will Guarantee payment of
the Securities on the same terms and conditions as those set forth in the
Indenture;




WHEREAS, Novamerican has formed the
Additional Subsidiary Guarantor for the purpose of merging the Additional
Subsidiary Guarantor with and into it in order to effect a name change from
Novamerican Steel Inc. to Barzel Industries Inc. in the State of Delaware in
December 2008;




WHEREAS, following the name change
merger, the Additional Subsidiary Guarantor will be merged with and into
Novamerican and its existence will cease; and




WHEREAS, pursuant to Sections 9.01(1),
9.01(4) and 9.06 of the Indenture, the Trustee is authorized to execute and
deliver this Supplemental Indenture.




NOW THEREFORE, in consideration of the
foregoing and for good and valuable consideration, the receipt of which is
hereby acknowledged, Novamerican, the Company, the Additional Subsidiary
Guarantor, the other Subsidiary Guarantors and the Trustee mutually covenant and
agree for the equal and ratable benefit of the Holders of the Notes as
follows:




SECTION 1.  Capitalized
Terms.  Capitalized terms used herein but not defined shall
have the meanings assigned to them in the Indenture.




SECTION 2.  [intentionally
omitted]




SECTION 3.  Guaranties.  The
Additional Subsidiary Guarantor hereby unconditionally and irrevocably
guarantees, jointly and severally, to each Holder and to the







Trustee
and its successors and assigns (a) the full and punctual payment of principal of
and interest on the Securities when due, whether at maturity, by acceleration,
by redemption or otherwise, and all other monetary obligations of the Company
under the Indenture and the Securities and (b) the full and punctual performance
within applicable grace periods of all other obligations of the Company under
the Indenture and the Securities. The Additional Subsidiary Guarantor further
agrees that the Guaranteed Obligations may be extended or renewed, in whole or
in part, without notice to or further assent from the Additional Subsidiary
Guarantor and that the Additional Subsidiary Guarantor will remain bound under
this Supplemental Indenture notwithstanding any extension or renewal of any
Obligation.




The Additional Subsidiary Guarantor
waives presentation to, demand of, payment from and protest to the Company of
any of the Guaranteed Obligations and also waives notice of protest for
nonpayment. The Additional Subsidiary Guarantor waives notice of any default
under the Securities or the Guaranteed Obligations.  The obligations
of the Additional Subsidiary Guarantor hereunder shall not be affected by (a)
the failure of any Holder or the Trustee to assert any claim or demand or to
enforce any right or remedy against the Company or any other Person (including
any Guarantor) under the Indenture, this Supplemental Indenture, the Securities
or any other agreement or otherwise; (b) any extension or renewal of any
thereof; (c) any rescission, waiver, amendment or modification of any of the
terms or provisions of the Indenture, this Supplemental Indenture, the
Securities or any other agreement; (d) the release of any security held by any
Holder or the Trustee for the Guaranteed Obligations or any of them; (e) the
failure of any Holder or the Trustee to exercise any right or remedy against any
other guarantor of the Guaranteed Obligations; or (f) except as set forth in
Section 8 of this Supplemental Indenture, any change in the ownership of the
Additional Subsidiary Guarantor.




The Additional Subsidiary Guarantor
further agrees that its Note Guarantee herein constitutes a guarantee of
payment, performance and compliance when due (and not a guarantee of collection)
and waives any right to require that any resort be had by any Holder or the
Trustee to any security held for payment of the Guaranteed
Obligations.




Except as expressly set forth in
Section 8.01(b) of the Indenture and Sections 4 and 8 of this Supplemental
Indenture, the obligations of the Additional Subsidiary Guarantor hereunder
shall not be subject to any reduction, limitation, impairment or termination for
any reason, including any claim of waiver, release, surrender, alteration or
compromise, and shall not be subject to any defense of setoff, counterclaim,
recoupment or termination whatsoever or by reason of the invalidity, illegality
or unenforceability of the Guaranteed Obligations or otherwise. Without limiting
the generality of the foregoing, the obligations of the Additional Subsidiary
Guarantor herein shall not be discharged or impaired or otherwise affected by
the failure of any Holder or the Trustee to assert any claim or demand or to
enforce any remedy under the Indenture, this Supplemental Indenture, the
Securities or any other agreement, by any waiver or modification of any thereof,
by any default, failure or delay, willful or otherwise, in the performance of
the obligations, or by any other act or thing or omission or delay to do any
other act or thing which may or might in any manner or to any extent vary the
risk of the Additional Subsidiary Guarantor or would otherwise operate as a
discharge of the Additional Subsidiary Guarantor as a matter of law or
equity.




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The Additional Subsidiary Guarantor
further agrees that its Note Guarantee shall remain in full force and effect
until payment in full of all the Guaranteed Obligations or such Note Guarantee
is released in compliance with Section 8 of this Supplemental Indenture or upon
the merger or the sale of all the Capital Stock or assets of the Additional
Subsidiary Guarantor in compliance with Section 4.06 or Article 5 of the
Indenture. The Additional Subsidiary Guarantor further agrees that its Guarantee
herein shall continue to be effective or be reinstated, as the case may be, if
at any time payment, or any part thereof, of principal of or interest on any
Obligation is rescinded or must otherwise be restored by any Holder or the
Trustee upon the bankruptcy or reorganization of the Company or
otherwise.




In furtherance of the foregoing and not
in limitation of any other right which any Holder or the Trustee has at law or
in equity against the Additional Subsidiary Guarantor by virtue hereof, upon the
failure of the Company to pay the principal of or interest on any Obligation
when and as the same shall become due, whether at maturity, by acceleration, by
redemption or otherwise, or to perform or comply with any other Obligation, the
Additional Subsidiary Guarantor hereby promises to and shall, upon receipt of
written demand by the Trustee, forthwith pay, or cause to be paid, in cash, to
the Holders or the Trustee an amount equal to the sum of (A) the unpaid amount
of such Guaranteed Obligations, (B) accrued and unpaid interest on such
Guaranteed Obligations (but only to the extent not prohibited by law) and (C)
all other monetary Guaranteed Obligations of the Company to the Holders and the
Trustee.




The Additional Subsidiary Guarantor
agrees that, as between it, on the one hand, and the Holders and the Trustee, on
the other hand, (i) the maturity of the Guaranteed Obligations hereby may be
accelerated as provided in Article 6 of the Indenture for the purposes of the
Additional Subsidiary Guarantor’s Note Guarantee herein, notwithstanding any
stay, injunction or other prohibition preventing such acceleration in respect of
the Guaranteed Obligations guaranteed hereby, and (ii) in the event of any
declaration of acceleration of such Guaranteed Obligations as provided in
Article 6 of the Indenture, such Guaranteed Obligations (whether or not due and
payable) shall forthwith become due and payable by the Additional Subsidiary
Guarantor for the purposes of this Supplemental Indenture.




The Additional Subsidiary Guarantor
also agrees to pay any and all costs and expenses (including reasonable
attorneys’ fees) incurred by the Trustee or any Holder in enforcing any rights
under this Section 3.




SECTION 4. Limitation on
Liability.  Any term or provision of the Indenture or this
Supplemental Indenture to the contrary notwithstanding, the maximum aggregate
amount of the Guaranteed Obligations guaranteed hereunder by the Additional
Subsidiary Guarantor shall not exceed the maximum amount that can be hereby
guaranteed without rendering the Indenture or this Supplemental Indenture, as it
relates to the Additional Subsidiary Guarantor, voidable under applicable law
relating to fraudulent conveyance or fraudulent transfer or similar laws
affecting the rights of creditors generally.




SECTION 5. Successors and
Assigns.  This Supplemental Indenture shall be binding upon the
Additional Subsidiary Guarantor and its successors and assigns and shall inure
to the benefit of the successors and assigns of the Trustee and the Holders and,
in the event of any transfer or assignment of rights by any Holder or the
Trustee, the rights and privileges




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conferred
upon that party in the Indenture or this Supplemental Indenture and in the
Securities shall automatically extend to and be vested in such transferee or
assignee, all subject to the terms and conditions of the Indenture and this
Supplemental Indenture.




SECTION 6.  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 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.




SECTION 7.  Modification.  No
modification, amendment or waiver of any provision of this Supplemental
Indenture, nor the consent to any departure by the Additional Subsidiary
Guarantor 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 Additional Subsidiary Guarantor in any case shall
entitle the Additional Subsidiary Guarantor to any other or further notice or
demand in the same, similar or other circumstances.




SECTION 8. Release.  The
Additional Subsidiary Guarantor will be released from its obligations under the
Indenture and this Supplemental Indenture (other than any obligation that may
have arisen under Section 9 of this Supplemental Indenture), in accordance with,
and in compliance with, the provisions of Section 10.06 of the
Indenture.




SECTION 9.  Contribution.  If
the Additional Subsidiary Guarantor makes a payment under its Note Guarantee, it
shall be entitled upon payment in full of all Guaranteed Obligations under the
Indenture and this Supplemental Indenture to a contribution from each other
Guarantor in an amount equal to such other Guarantor’s pro rata portion of such
payment based on the respective net assets of all the Guarantors at the time of
such payment determined in accordance with GAAP.




SECTION 10.  No Recourse Against
Others.  A director, officer, incorporator, employee or
stockholder, as such, of the Additional Subsidiary Guarantor shall not have any
liability for any obligations of Novamerican, the Company or any Subsidiary
Guarantor (including the Additional Subsidiary Guarantor) under the Securities,
the Indenture, this Supplemental Indenture, the Security Documents, the
Intercreditor Agreement or any Intercompany Note Document or for any claim based
on, in respect of or by reason of such obligations or their creation. By
accepting a Security, each Holder shall waive and release all such liability.
The waiver and release shall be part of the consideration for the issue of the
Securities.




SECTION 11.  Governing
Law.  This Supplemental Indenture shall be governed by, and
construed in accordance with, the laws of the State of New York.




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SECTION 12.  Multiple
Originals.  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. One signed copy is enough to prove this
Supplemental Indenture.




SECTION 13.  Headings.  The
headings of the Sections of this Supplemental Indenture have been inserted for
convenience of reference only, are not intended to be considered a part hereof
and shall not modify or restrict any of the terms or provisions
hereof.




SECTION 14. Full Force and
Effect.  Except as expressly amended hereby, each provision of
the Indenture shall remain in full force and effect; and all the Indenture’s
provisions with respect to the Trustee’s rights, privileges, immunities, powers
and duties shall be applicable in respect hereof as fully and with like effect
as if set forth herein in full, with such omissions, variations or insertions,
if any, as may be appropriate to make the same conform to this Supplemental
Indenture.  From and after the date hereof, this Supplemental
Indenture shall form a part of the Indenture for all purposes, and every Holder
of Securities heretofore or hereafter authenticated and delivered shall be bound
hereby.




SECTION 15. Trustee.  All
recitations or recitals contained in this Supplemental Indenture are made by and
on behalf of the Company and the Guarantors only, and the Trustee is in no way
responsible for the correctness of any statement herein contained or for the
validity or sufficiency of this Supplemental Indenture.  The execution
by the Trustee of this Supplemental Indenture shall not be construed to be an
approval or disapproval by the Trustee of the advisability of the action being
taken herein by the Company and the Guarantors.




[remainder
of page intentionally left blank]




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




BARZEL
      INDUSTRIES INC., as Additional Subsidiary Guarantor,By
            /s/
      Corrado De GasperisName:
      Corrado De Gasperis
              Title:
      President and TreasurerNOVAMERICAN
      STEEL FINCO INC., as Issuer,By
            /s/
      Corrado De GasperisName:
      Corrado De Gasperis
              Title:
      President and TreasurerNOVAMERICAN
      STEEL INC. f/k/a Symmetry Holdings Inc., as Guarantor,By
            /s/
      Corrado De GasperisName:
      Corrado De Gasperis
              Title:
      Chief Executive OfficerNOVAMERICAN
      STEEL HOLDINGS INC., as Subsidiary Guarantor,By
            /s/
      Corrado De GasperisName:
      Corrado De Gasperis
              Title:
      President and Treasurer


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NOVAMERICAN
      STEEL U.S. INC. f/k/a Integrated Steel Industries, Inc., as Subsidiary
      Guarantor,By
            /s/
      Corrado De GasperisName:
      Corrado De Gasperis
              Title:
      President and TreasurerAMERICAN
      STEEL AND ALUMINUM CORPORATION, as Subsidiary
Guarantor,By
            /s/
      Corrado De GasperisName:
      Corrado De Gasperis
              Title:
      President and TreasurerNOVA
      TUBE AND STEEL, INC., as Subsidiary Guarantor,By
            /s/
      Corrado De GasperisName:
      Corrado De Gasperis
              Title:
      President and TreasurerNOVAMERICAN
      TUBE HOLDINGS, INC., as Subsidiary Guarantor,By
            /s/
      Corrado De GasperisName:
      Corrado De Gasperis
              Title:
      President and Treasurer





[Signature
Page to Supplemental Indenture]





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NOVA
      TUBE INDIANA, LLC, as Subsidiary Guarantor,By
            /s/
      Corrado De GasperisName:
      Corrado De Gasperis
              Title:
      President and TreasurerTHE
      BANK OF NEW YORK MELLON f/k/a The Bank of New York, as
Trusteeby
            /s/
      Christopher GreeneName:
      Christopher Greene
              Title:
      Vice President





ACKNOWLEDGED:
                
                BNY
      TRUST COMPANY OF CANADA,
                as
      Canadian Collateral Agentby
              /s/
      George A. BraggName:  George
      A. Bragg
                Title:  Vice-President






































[Signature
Page to Supplemental Indenture]





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