EXHIBIT 5.1


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                                                                December 5, 2003




GUSAP Partners and the Subsidiary Guarantors
c/o Gerdau Ameristeel US Inc.
5100 West Lemon Street, Suite 312
Tampa, Florida
United States, 33609


                     RE:   REGISTRATION STATEMENT ON FORM F-4

Dear Sirs/Mesdames:

            We have acted as Canadian and United States counsel to Gerdau
Ameristeel Corporation, an Ontario corporation ("Gerdau Ameristeel"), GUSAP
Partners, a Delaware general partnership ("GUSAP", and together with Gerdau
Ameristeel, the "Issuers"), and each of the entities listed on Schedule A hereto
(collectively, the "Subsidiary Guarantors"), in connection with the exchange
offer by the Issuers and the Subsidiary Guarantors of US $405,000,000 principal
amount of the Issuers' 10 3/8% Senior Notes due 2011 (the "Exchange Notes")
together with the accompanying unsecured guarantees of the Subsidiary Guarantors
(the "Exchange Guarantees", and together with the Exchange Notes, the "Exchange
Securities"). The Issuers and the Subsidiary Guarantors are filing, on the date
hereof, with the Securities and Exchange Commission (the "Commission") under the
Securities Act of 1933, as amended (the "Securities Act"), a Registration
Statement (including a prospectus dated of even date therewith and forming a
part of the Registration Statement, the "Prospectus") on a combined Form F-10
and Form F-4 (collectively, the "Registration Statement") relating to the
Issuers' and the Subsidiary Guarantors' offer to exchange the Exchange
Securities for all of the outstanding US $405,000,000 principal amount 10 3/8%
Senior Notes due 2011 and the accompanying guarantees by the Subsidiary
Guarantors (collectively, the "Existing Securities"). The Exchange Securities
will be issued, and the Existing Securities were issued, pursuant to an
indenture (the "Indenture") dated as of June 27, 2003 among the Issuers, the
Subsidiary Guarantors and SouthTrust Bank, as trustee (the "Trustee"). This
opinion is being furnished to you in accordance with the requirements of Item
601(b)(5) of Regulation S-K under the Securities Act.

            We have participated in the preparation of and, where applicable,
have examined an executed copy of each of the following:

      (a)   the Registration Statement (including the Prospectus);

      (b)   the Indenture, which includes the terms and conditions of the
            Exchange Guarantees and the form of Exchange Note (filed as Exhibit
            7.1 to the Registration Statement on Form F-10);

      (c)   the Registration Rights Agreement dated June 27, 2003, by and among
            the Issuers, the Subsidiary Guarantors and the initial purchasers of
            the Existing Notes (filed as Exhibit 2.1 to the Registration
            Statement on Form F-10);

      (d)   the statement of partnership existence (including amendments
            thereto) and amended and restated general partnership agreement of
            GUSAP (filed as Exhibits 3.1 and 3.2, respectively, to the
            Registration Statement on Form F-4);

      (e)   a consent of the managers of GUSAP relating to the Exchange Offer,
            the Registration Rights Agreement and the Indenture, including the
            issuance of the Exchange Notes and related matters; and

      (f)   the Form T-1 of the Trustee (filed as Exhibit 25.1 to the
            Registration Statement on Form F-4).

            We have also made those investigations and examined originals or
copies, certified or otherwise identified to our satisfaction, of those
certificates of public officials and of those other certificates, documents and
records as we considered necessary or relevant for purposes of the opinions
expressed below.

            In our examination, we have assumed the genuineness of all
signatures, the legal capacity of individuals signing any documents, the
authenticity of all documents submitted to us as originals and the conformity to
authentic original documents of all documents submitted to us as certified,
conformed, telecopied or photocopied copies. In making our examination of
documents executed or to be executed, we have assumed that each of the parties
thereto, other than GUSAP and the Subsidiary Guarantors, had or will have the
corporate or other power and capacity to enter into, and to perform its
obligations thereunder and have also assumed the due authorization, execution
and delivery by such parties of such documents and the validity and binding
effect thereof on such parties.

            With respect to the opinions relating to the Exchange Guarantees of
each of the Subsidiary Guarantors in clause (b) below, we have relied solely,
and without independent verification, upon opinions of local counsel in the
jurisdiction of organization of each of the Subsidiary Guarantors (as set forth
in Schedule A), each dated June 27, 2003, as to the due authorization of the
Registration Rights Agreement and the Indenture (which includes the Exchange
Guarantees).

            Based upon the foregoing and subject to the assumptions,
limitations, exceptions and qualifications herein stated, we are of the opinion
that:

            (a)   the Exchange Notes to be issued by GUSAP have been duly
                  authorized by GUSAP and when issued, executed and delivered by
                  GUSAP and Gerdau Ameristeel and authenticated by the Trustee
                  pursuant to the terms and conditions of the Indenture and
                  exchanged for the Existing Notes as contemplated in the
                  Registration Statement, the Exchange Notes will be validly
                  issued and outstanding and will constitute valid and legally
                  binding obligations of GUSAP, enforceable against GUSAP in
                  accordance with their terms and the terms of the Indenture,
                  except to the extent that enforcement may be limited by (i)
                  bankruptcy, insolvency, reorganization, moratorium, fraudulent
                  conveyance or other similar laws now or hereafter in effect
                  relating to creditors' rights generally, and (ii) general
                  principles of equity (regardless of whether enforceability is
                  considered in a proceeding at law or in equity); and

            (b)   each Exchange Guarantee of the applicable Subsidiary Guarantor
                  will constitute a valid and binding obligation of such
                  Subsidiary Guarantor, enforceable against such Subsidiary
                  Guarantor in accordance with its terms, except, in each case,
                  to the extent that enforcement thereof may be limited by (i)
                  bankruptcy, insolvency, reorganization, moratorium, fraudulent
                  conveyance or other similar laws now or hereafter in effect
                  relating to creditors' rights generally, and (ii) general
                  principles of equity (regardless of whether enforceability is
                  considered in a proceeding at law or in equity).

            With respect to any opinions addressing the corporate or partnership
law of the State of Delaware, you are aware that no members of our firm are
admitted to the Bar of the State of Delaware and that such opinions are based
upon our general familiarity with the corporate or partnership law of the State
of Delaware as a result of our prior involvement in transactions of a similar
nature involving such law.

            The information set out in this opinion letter is as of the date of
this opinion letter, and you should infer no obligation on our part to advise
you of changes, material or otherwise, arising from matters subsequently brought
to our attention and you should infer no obligation on our part to provide you
with supplemental information as of a later date.

            We hereby consent to the filing of this opinion with the Commission
as an exhibit to the Registration Statement. We also consent to the reference to
our firm name under the caption "Legal Matters" and "Description of Notes -
Enforceability of Judgments" in the Prospectus. In giving this consent, we do
not thereby admit that we are included in the category of persons whose consent
is required under Section 7 of the Securities Act or the rules and regulations
of the Commission.

                                       Very truly yours,


                                       /s/ Torys LLP

                                   SCHEDULE A

       NAME AND JURISDICTION OF INCORPORATION OF EACH SUBSIDIARY GUARANTOR

Gerdau Ameristeel MRM Special Sections Inc. (Saskatchewan)

3038482 Nova Scotia Company (Nova Scotia)

Pasug LLC (Delaware)

Gerdau USA Inc. (Delaware)

Gerdau Ameristeel US Inc. (Florida)

Porter Bros. Corporation (North Dakota)

MFT Acquisition, Corp. (Delaware)

1062316 Ontario Limited (Ontario)

Co-Steel Benefit Plans Inc. (Ontario)

1300554 Ontario Limited (Ontario)

1551533 Ontario Limited (Ontario)

Co-Steel C.S.M. Corp. (Delaware)

Gerdau Ameristeel Perth Amboy Inc. (New Jersey)

Raritan River Urban Renewal Corporation (New Jersey)

Gerdau Ameristeel Lake Ontario Inc. (Delaware)

Co-Steel Benefit Plans USA Inc. (Delaware)

Gerdau Ameristeel Sayreville Inc. (Delaware)

N.J.S.C. Investment Co., Inc. (New Jersey)