<PAGE>
                                                                     EXHIBIT 4.6
                                                                     -----------
 
Unless this Note is presented by an authorized representative of The Depository
Trust Company, a New York corporation ("DTC"), to the Company (as defined below)
or its agent for registration of transfer, exchange, or payment, and any Note
issued is registered in the name of Cede & Co. or in such other name as is
requested by an authorized representative of DTC (and any payment is made to
Cede & Co. or to such other entity as is requested by an authorized
representative of DTC), ANY TRANSFER, PLEDGE, OR OTHER USE HEREOF FOR VALUE OR
OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner
hereof, Cede & Co., has an interest herein.

REGISTERED                                                      PRINCIPAL AMOUNT
No.:  1                                                             $150,000,000

CUSIP No.:  78375P AA5

                              RYERSON TULL, INC.
                         8 1/2% NOTE DUE JULY 15, 2001

     RYERSON TULL, INC., a corporation duly organized and existing under the
laws of the State of Delaware (hereinafter called the "Company," which term
shall include any successor Person under the Indenture hereinafter referred to),
for value received, hereby promises to pay to CEDE & CO., or registered assigns,
upon presentation, the principal sum of ONE HUNDRED FIFTY MILLION DOLLARS on
July 15, 2001 and to pay interest on the outstanding principal amount thereon
from July 3, 1996, or from the most recent Interest Payment Date to which
interest has been paid or duly provided for, semi-annually in arrears on January
15 and July 15 in each year, commencing on January 15, 1997, at the rate of 
8 1/2% per annum, until the entire principal hereof is paid or made available
for payment. The interest so payable and punctually paid or duly provided for on
any Interest Payment Date will, as provided in the Indenture, be paid to the
Person in whose name this Security (or one or more Predecessor Securities) is
registered at the close of business on the Regular Record Date for such interest
which shall be January 1 or July 1 (whether or not a Business Day), as the case
may be, next preceding such Interest Payment Date. Any such interest not so
punctually paid or duly provided for shall forthwith cease to be payable to the
Holder on such Regular Record Date and may either be paid to the Person in whose
name this Security (or one or more Predecessor Securities) is registered at the
close of business on a Special Record Date for the payment of such Defaulted
Interest to be fixed by the Trustee, notice whereof shall be given to Holders of
Securities of this series not more than 15 days and not less than 10 days prior
to such Special Record Date, or may be paid at any time in any other lawful
manner not inconsistent with the requirements of any securities exchange on
which the Securities of this series may be listed, and upon such notice as may
be required by such exchange, all as more fully provided in the Indenture.
Payment of the principal of, and premium, if any, on, and interest on this
Security will be made at the office or agency of the Company maintained for that
purpose in the Borough of Manhattan, City of New York, or elsewhere as provided
in the Indenture, in such coin or currency of the United States of
<PAGE>
 
America as at the time of payment is legal tender for payment of public and
private debts; provided, however, that, unless this Security is in registered
global form, at the option of the Company payment of interest on any Interest
Payment Date may be made by check mailed to the address of the Person entitled
thereto as such address shall appear in the Security Register on the Regular
Record Date.

     Each Security of this series is one of a duly authorized issue of
securities of the Company (herein called the "Securities"), issued and to be
issued in one or more series under an Indenture, dated as of July 1, 1996
(herein called the "Indenture"), between the Company and The Bank of New York
(herein called the "Trustee," which term includes any successor trustee under
the Indenture with respect to the series of which this Security is a part), 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 Trustee and the Holders of the
Securities and of the terms upon which the Securities are, and are to be,
authenticated and delivered. This Security is one of the series designated on
the first page hereof, and such series is limited in aggregate principal amount
to $150,000,000.

     Securities of this series will be subject to redemption, in whole or in
part, at any time or from time to time, at the option of the Company on at least
30 days' prior notice by mail at a Redemption Price equal to the greater of (i)
100% of the principal amount of the Securities to be redeemed or (ii) the sum of
the present values of the remaining scheduled payments of principal and interest
thereon discounted to the Redemption Date on a semiannual basis (assuming a 360-
day year consisting of twelve 30-day months) at the Treasury Rate (as defined
herein) plus 50 basis points, plus accrued but unpaid interest to the Redemption
Date, but interest installments whose Stated Maturity is on or prior to such
Redemption Date will be payable to the Holders of such Securities, or one or
more Predecessor Securities, of record at the close of business on the relevant
Record Dates referred to on the first page hereof, all as provided in the
Indenture. On and after the Redemption Date, interest will cease to accrue on
the Securities or portions of Securities called for redemption on such date.
Securities of this series may be redeemed in part but only in integral multiples
of $1,000.

     "Treasury Rate" means, with respect to any Redemption Date, the rate per
annum equal to the semiannual equivalent yield to maturity of the Comparable
Treasury Issue, assuming a price for such Comparable Treasury Issue (expressed
as a percentage of its principal amount) equal to the Comparable Treasury Price
for such redemption date.

     "Comparable Treasury Issue" means the United States Treasury security
selected by an Independent Investment Banker as having a maturity comparable to
the remaining term of this series of Securities that would be utilized, at the
time of selection and in accordance with customary financial practice, in
pricing new issues of corporate debt securities of comparable maturity to the
remaining term of the Securities. "Independent Investment Banker" means one of
the Reference Treasury Dealers appointed by the Trustee after consultation with
the Company.
<PAGE>
 
     "Comparable Treasury Price" means, with respect to any Redemption Date, (i)
the average of the bid and asked prices for the Comparable Treasury Issue
(expressed in each case as a percentage of its principal amount) on the third
Business Day preceding such Redemption Date, as set forth in the daily
statistical release (or any successor release) published by the Federal Reserve
Bank of New York and designated "Composite 3:30 p.m. Quotations for U.S.
Government Securities" or (ii) if such release (or any successor release) is not
published or does not contain such prices on such Business Day, (A) the average
of the Reference Treasury Dealer Quotations for such Redemption Date, after
excluding the highest and lowest such Reference Treasury Dealer Quotations, or
(B) if the Trustee obtains fewer than three such Reference Treasury Dealer
Quotations, the average of all such Quotations.

     "Reference Treasury Dealer" means Goldman, Sachs & Co. and CS First Boston
Corporation, and their respective successors; provided, however, that if any of
the foregoing shall cease to be a primary U.S. Government securities dealer in
New York City (a "Primary Treasury Dealer") the Company shall substitute
therefor another Primary Treasury Dealer.

     "Reference Treasury Dealer Quotations" means, with respect to each
Reference Treasury Dealer and any Redemption Date, the average, as determined by
the Trustee, of the bid and asked prices for the Comparable Treasury Issue
(expressed in each case as a percentage of its principal amount) quoted in
writing to the Trustee by such Reference Treasury Dealer at 5:00 p.m. on the
third Business Day preceding such Redemption Date.

     Any notice to the Holders of such a redemption need not set forth the
Redemption Price but need only set forth the calculation thereof as described in
the third paragraph of this Security. The Redemption Price, calculated as
aforesaid, shall be set forth in an Officers' Certificate delivered to the
Trustee no later than two Business Days prior to the Redemption Date.

     In the event of redemption of this Security in part only, a new Security or
Securities of this series and of like tenor for the unredeemed portion thereof
will be issued in the name of the Holder hereof upon cancellation hereof.

     No sinking fund shall be established for the benefit of the Securities.

     The Indenture contains provisions for defeasance at any time of (a) the
entire indebtedness of the Company on this Security and (b) certain restrictive
covenants and the related defaults and Events of Default applicable to the
Company, in each case, upon compliance by the Company with certain conditions
set forth in the Indenture, which provisions apply to this Security.

     If an Event of Default with respect to Securities of this series shall
occur and be continuing, the principal of, and the premium, if any, and accrued
interest on, the Securities of this series may be declared due and payable in
the manner and with the effect provided in the Indenture.
<PAGE>
 
     As provided in and subject to the provisions of the Indenture, the Holder
of this Security shall not have the right to institute any proceeding with
respect to the Indenture or for the appointment of a receiver or trustee or for
any other remedy thereunder, unless such Holder shall have previously given the
Trustee written notice of a continuing Event of Default with respect to the
Securities of this series, the Holders of not less than 25% in principal amount
of the Securities of this series at the time Outstanding shall have made written
request to the Trustee to institute proceedings in respect of such Event of
Default, as Trustee, and offered the Trustee reasonable indemnity and the
Trustee shall not have received from the Holders of a majority in principal
amount of Securities of this series at the time Outstanding a direction
inconsistent with such request, and the Trustee shall have failed to institute
any such proceeding for 60 days after receipt of such notice, request and offer
of indemnity. The foregoing shall not apply to any suit instituted by the Holder
of this Security for the enforcement of any payment of principal hereof or any
interest hereon on or after any respective due dates expressed herein.

     The Indenture permits, with certain exceptions as therein provided, the
amendment thereof and the modification of the rights and obligations of the
Company and the rights of the Holders of the Securities of each series to be
affected under the Indenture at any time by the Company and the Trustee with the
consent of the Holders of not less than a majority in principal amount of the
Outstanding Securities of each series of Securities then Outstanding affected
thereby. The Indenture also contains provisions permitting the Holders of
specified percentages in principal amount of the Securities of each series at
the time Outstanding, on behalf of the Holders of all Securities of such series,
to waive compliance by the Company with certain provisions of the Indenture and
certain past defaults under the Indenture and their consequences. Any such
consent or waiver by the Holder of this Security shall be conclusive and binding
upon such Holder and upon all future Holders of this Security and of any
Security issued upon the registration of transfer hereof or in exchange herefor
or in lieu hereof, whether or not notation of such consent or waiver is made
upon this Security.

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

     As provided in the Indenture and subject to certain limitations therein set
forth, the transfer of this Security is registrable in the Security Register,
upon surrender of this Security for registration of transfer at the office or
agency of the Company in any Place of Payment where the principal of, premium,
if any, on, and interest on this Security are payable duly endorsed by, or
accompanied by a written instrument of transfer in form satisfactory to the
Company and the Security Registrar duly executed by, the Holder hereof or his
attorney duly authorized in writing, and thereupon one or more new Securities of
this series and of like tenor, of authorized denominations and for the same
aggregate principal amount, will be issued to the designated transferee or
transferees.
<PAGE>
 
     The Securities of this series are issuable only in registered form without
coupons in denominations of $1,000 and any integral multiple thereof.  As
provided in the Indenture and subject to certain limitations therein set forth,
Securities of this series are exchangeable for a like aggregate principal amount
of Securities of this series and of like tenor of a different authorized
denomination, as requested by the Holder surrendering the same.

     No service charge shall be made for any such registration of transfer or
exchange, but the Company may require payment of a sum sufficient to cover any
tax or other governmental charge payable in connection therewith.

     Prior to due presentment of this Security for registration of transfer, the
Company, the Trustee and any agent of the Company or the Trustee may treat the
Person in whose name this Security is registered as the owner hereof for all
purposes, whether or not this Security be overdue, and none of the Company, the
Trustee or any such agent shall be affected by notice to the contrary.

     No recourse under or upon any obligation, covenant or agreement contained
in the Indenture or in this Security, or because of any indebtedness evidenced
thereby, shall be had against any promoter, as such, or against any past,
present or future stockholder, officer or trustee, as such, of the Company or of
any successor, either directly or through the Company or any successor, under
any rule of law, statute or constitutional provision or by the enforcement of
any assessment or by any legal or equitable proceeding or otherwise, all such
liability being expressly waived and released by the acceptance of this Security
by the Holder thereof and as part of the consideration for the issue of the
Securities of this series.

     All terms used in this Security which are defined in the Indenture shall
have the meanings assigned to them in the Indenture.

     THE INDENTURE AND THIS SERIES OF SECURITIES, INCLUDING THIS SECURITY, SHALL
BE GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF NEW
YORK, WITHOUT GIVING EFFECT TO THE CONFLICT OF LAW PROVISIONS THEREOF.

     Pursuant to a recommendation promulgated by the Committee on Uniform
Security Identification Procedures, the Company has caused "CUSIP" numbers to be
printed on the Securities of this series as a convenience to the Holders of such
Securities.  No representation is made as to the correctness or accuracy of such
CUSIP numbers as printed on the Securities, and reliance may be placed only on
the other identification numbers printed hereon.

                                      -5-

<PAGE>
 
     Unless the certificate of authentication hereon has been executed by or on
behalf of the Trustee by manual signature, this Security shall not be entitled
to any benefit under the Indenture or be valid or obligatory for any purpose.

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


                              RYERSON TULL, INC.



                              By:_______________________
                                  Neil S. Novich
                                  Chairman


     [SEAL]                   By:_______________________
                                  Terence R. Rogers
                                  Treasurer
Attest


By:_________________________
    George A. Ranney, Jr.
    Secretary



Dated: March 16, 1999

TRUSTEE'S CERTIFICATE OF AUTHENTICATION:

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

THE BANK OF NEW YORK,
as Trustee


By:________________________
    Authorized Signatory

                                      -6-
<PAGE>
 
                                ASSIGNMENT FORM

                   FOR VALUE RECEIVED, the undersigned hereby
                       sells, assigns and transfers unto


     PLEASE INSERT SOCIAL SECURITY
     OR OTHER IDENTIFYING NUMBER OF ASSIGNEE


          ----------------------------------------------------


          ----------------------------------------------------


 . . . . . . . . . . . . . .. . . . . . . . . . . . . .. . . . . . . . . . . . . 
             (Please Print or Typewrite Name and Address including
                             Zip Code of Assignee)


 . . . . . . . . . . . . . .. . . . . . . . . . . . . .. . . . . . . . . . . . . 
the within Security of Ryerson Tull, Inc. and hereby does irrevocably constitute
and appoint


 . . . . . . . . . . . . . .. . . . . . . . . . . . . .. . . . . . . . . Attorney
to transfer said Security on the books of the within named Company with full
power of substitution in the premises.

Dated:         . . . . . .         . . . . . . . . . . . . . .

                                   . . . . . . . . . . . . . .

NOTICE:  The signature to this assignment must correspond with the name as it
appears on the first page of the within Security in every particular, without
alteration or enlargement or any change whatever.


               Signature Guarantee:
                                   ----------------------------

                                      -7-