As filed with the Securities and Exchange Commission on July 1, 2003
                                                Registration Statement No.
                                                                          ------

================================================================================


                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549


                                    FORM S-3

                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933

                               A. M. CASTLE & CO.
              ----------------------------------------------------
             (Exact Name of Registrant as Specified in Its Charter)

                  Maryland                                       36-0879160
        -----------------------------                         -----------------
       (State or Other Jurisdiction                          (I.R.S. Employer
     of Incorporation or Organization)                       Identification No.)

                              3400 North Wolf Road
                          Franklin Park, Illinois 60131
                                 (847) 455-7111
                -------------------------------------------------
               (Address, Including Zip Code, and Telephone Number,
        Including Area Code, of Registrant's Principal Executive Offices)

                              Jerry M. Aufox, Esq.
                               A. M. Castle & Co.
                              3400 North Wolf Road
                          Franklin Park, Illinois 60131
                            Telephone: (847) 349-2516
             --------------------------------------------------------
            (Name, Address, Including Zip Code, and Telephone Number,
                   Including Area Code, of Agent for Service)

                                   Copies to:
                             William E. Doran, Esq.
                             Sachnoff & Weaver, Ltd.
                         30 S. Wacker Drive, 29th Floor
                          Chicago, Illinois 60606-7484
                                 (312) 207-6412

     Approximate date of commencement of proposed sale to the public:  From time
to time after this registration statement becomes effective.

     If the only  securities  being  registered  on this form are to be  offered
pursuant to dividend or interest  reinvestment plans, please check the following
box. [ ]

     If any of the securities being registered on this form are to be offered on
a delayed or continuous  basis  pursuant to Rule 415 under the Securities Act of
1933, other than securities offered only in connection with dividend or interest
reinvestment plans, check the following box. [X]

     If this form is filed to  register  additional  securities  for an offering
pursuant to Rule 462(b) under the  Securities  Act,  check the following box and
list the Securities Act registration  statement number of the earlier  effective
registration statement for the same offering. [ ]

     If this form is a  post-effective  amendment  filed pursuant to Rule 462(c)
under the  Securities  Act,  check the following box and list the Securities Act
registration  statement number of the earlier effective  registration  statement
for the same offering. [ ]

     If delivery of the  prospectus is expected to be made pursuant to Rule 434,
please check the following box. [ ]






                              CALCULATION OF REGISTRATION FEE

                                              Proposed      Proposed
                                               Maximum       Maximum
  Title of Each                               Offering      Aggregate         Amount of
Class of Securities         Amount to be      Price Per     Offering        Registration
 to be Registered           Registered(1)     Share(2)      Price(2)             Fee
 ----------------           -------------     --------      --------             ---
                                                              
Common Stock, $0.01 par       2,809,995        $5.00        $14,049,975      $1,136.64
   value per share

     (1)  In  accordance  with Rule 416 under the  Securities  Act of 1933,  the
          common stock offered  hereby shall also be deemed to cover  additional
          securities  to be offered or issued in  connection  with stock splits,
          stock dividends or similar transactions.

     (2)  Estimated  solely for  purposes  of  computing  the  registration  fee
          pursuant to Rule 457(c) under the  Securities Act of 1933 on the basis
          of the on the  average of the high and low sales  prices  reported  on
          AMEX on June 26, 2003.

          The  registrant  amends this  registration  statement  on such date or
dates as may be necessary to delay its effective date until the registrant shall
file a further  amendment  which  specifically  states  that  this  registration
statement shall  thereafter  become effective in accordance with section 8(a) of
the Securities  Act of 1933, as amended,  or until this  registration  statement
shall become  effective on such date as the Securities and Exchange  Commission,
acting pursuant to said section 8(a), may determine.

================================================================================





The information in this prospectus is not complete and may be changed. The
Selling Stockholders may not sell these securities until the registration
statement filed with the Securities and Exchange Commission is effective. This
prospectus is not an offer to sell these securities and it is not soliciting an
offer to buy these securities in any state where the offer or sale is not
permitted.



                   Subject to Completion, dated July 1, 2003.

                                2,809,995 Shares

                                       of

                               A. M. CASTLE & CO.

                     Common Stock, par value $0.01 per share

          The Selling Stockholders  identified in this prospectus may sell up to
2,809,995 shares of our common stock. If the Selling  Stockholders elect to sell
their shares,  they may do so from time to time privately at prices individually
negotiated  with the  purchasers,  publicly in transactions on the Chicago Stock
Exchange or the American Stock Exchange,  or as otherwise  discussed in "Plan of
Distribution."  We will not receive any proceeds  from the sale of shares by the
Selling Stockholders. See "Use of Proceeds."

          Our common  stock is traded on the  American  Stock  Exchange  and the
Chicago  Stock  Exchange  under the  symbol  "CAS." On June 26,  2003,  the last
reported sale price of the common stock was $5.00.

          We will pay  certain  legal fees and other  expenses of certain of the
Selling Stockholders in this offering, except that all Selling Stockholders will
bear their own costs of any  brokerage  commissions  or  discounts  incurred  in
connection  with the sale of their  shares.  We have also  agreed  to  indemnify
certain of the  Selling  Stockholders  against  certain  liabilities,  including
liabilities under the Securities Act. See "Plan of Distribution."

          See "Risk  Factors"  beginning on page 5 for a  discussion  of factors
that you should  consider  before you invest in the common  stock being  offered
through this prospectus.

          Neither  the  Securities   and  Exchange   Commission  nor  any  other
regulatory body has approved or disapproved of these securities or passed on the
accuracy or adequacy of this prospectus. Any representation to the contrary is a
criminal offense.




                   This prospectus is dated [_________], 2003

                                       2




                                TABLE OF CONTENTS

                                                                 Page
                                                                 ----
AVAILABLE INFORMATION..............................................3
A.M. CASTLE & CO...................................................4
RISK FACTORS.......................................................5
USE OF PROCEEDS....................................................7
SELLING STOCKHOLDERS...............................................7
PLAN OF DISTRIBUTION...............................................8
VALIDITY OF STOCK.................................................10
EXPERTS...........................................................10


                              Available Information

          We file  reports,  proxy  statements  and other  information  with the
Securities and Exchange Commission ("SEC").  Those reports, proxy statements and
other information may be obtained:

o    At the Public Reference Rooms of the SEC in Washington, DC. Please call the
     SEC at  1-800-SEC-0330,  or  write  the  SEC  at  Securities  and  Exchange
     Commission,  Public Reference  Section,  Judiciary Plaza, 450 Fifth Street,
     N.W., Washington, DC 20549, for further information.

o    At the offices of the American Stock Exchange,  86 Trinity Place, New York,
     NY 10006; or

o    From the Internet site maintained by the Securities and Exchange Commission
     at  http://www.sec.gov,  which  contains  reports,  proxy  and  information
     statements and other information regarding issuers that file electronically
     with the Securities and Exchange Commission.

          We  have  filed  with  the  Securities   and  Exchange   Commission  a
registration  statement on Form S-3 under the Securities Act covering the shares
of common stock offered by this  prospectus.  As permitted by the Securities and
Exchange  Commission,   this  prospectus,   which  constitutes  a  part  of  the
registration  statement,  does not contain all the  information  included in the
registration  statement.   The  information  incorporated  by  reference  is  an
important part of this  prospectus,  and  information we file later with the SEC
will  automatically  update and supersede  this  information.  We incorporate by
reference  the documents  listed below and any future  filings made with the SEC
under Sections 13(a),  13(c), 14 or 15(d) of the Securities Exchange Act of 1934
until all of the  shares  offered by this  prospectus  have been sold or we have
filed with the SEC an amendment to the registration  statement  relating to this
offering which deregisters all securities then remaining unsold.

         We have previously filed the following documents with the Securities
and Exchange Commission under the Securities Exchange Act of 1934, as amended,
and they are incorporated into this prospectus by reference:

          (a)  Annual  Report on Form 10-K of A. M.  Castle & Co. for the fiscal
year ended December 31, 2002, filed on March 3, 2003;

          (b) Proxy  Statement  of A. M. Castle & Co. for the Annual  Meeting of
Stockholders held on April 24, 2003, filed on March 18, 2003;

          (c) Current Report on Form 8-K filed on May 6, 2003;

          (d) Quarterly  Report on Form 10-Q of A.M. Castle & Co. for the fiscal
quarter ended March 31,2003, filed on May 15, 2003; and

          (e)  The  description  of our  common  stock  contained  in the  Proxy
Statement of A. M. Castle & Co. for the Annual Meeting of  Stockholders  held on
April 26, 2001, filed on March 23, 2001.

                                       3




          You should rely only on the  information  incorporated by reference or
provided in this prospectus or any prospectus supplement. We have not authorized
anyone to provide you with information  that is different.  We are not making an
offer of these securities in any jurisdiction  where the offer is not permitted.
You should not assume that the  information in this prospectus or any prospectus
supplement or any other document incorporated by reference herein is accurate as
of any date other than the date of such document.

          On  request,  we  will  provide  anyone  who  receives  a copy of this
prospectus  with a copy  of any or all of the  documents  incorporated  in  this
prospectus by reference. Written or telephone requests for such copies should be
directed  to our  principal  office:  A. M.  Castle  & Co.,  Investor  Relations
Department, 3400 North Wolf Road, Franklin Park, Illinois 60131, (847) 455-7111.


          This  prospectus  contains  forward-looking  statements.  Some  of the
information   contained  or  incorporated  into  in  this  prospectus,   may  be
forward-looking  statements  under the federal  securities laws. Such statements
often  contain  words such as  "anticipates,"  "intends,"  "seeks,"  "believes,"
"estimates,"  "plans," and "expects." These statements discuss  expectations for
the future,  contain projections concerning the results of our operations or our
future  financial  condition  or state  other  forward-looking  information.  We
believe it is  important  to  communicate  our  expectations  to our  investors.
However,  there will be events in the future that we are not able to  accurately
predict  or over  which we have no  control.  The risk  factors  listed  in this
section,  as well as any other cautionary  language in this prospectus,  provide
examples of risks, uncertainties and events that may cause our actual results to
differ  materially  from the  expectations  we describe  in our  forward-looking
statements.  Before you invest in our common stock, you should be aware that the
occurrence  of the events  described in these risk factors and elsewhere in this
prospectus,  or in our other  publicly  filed reports which are or later will be
incorporated  herein,  could have a  material  adverse  effect on our  business,
operating results and financial condition.

                               A. M. CASTLE & CO.


          We are a distributor of highly  engineered metal and plastic materials
and a provider of value-added  services  associated  with these  materials.  Our
metal  materials are commonly  classified as either Ferrous (such as mild steel,
cast steel and cast iron) and Non-Ferrous (such as aluminum,  cooper,  brass and
lead).  Our  customers  are a wide  range of  industrial  companies  within  the
producer durable equipment sector of our economy.  We are classified as being in
the metals distribution  industry and we are known as a steel service center. We
deliver  highly  engineered  materials  for  critical  applications  where exact
conformance to specifications provided to us by our customers is essential.

          Our customer base includes a variety of companies in the durable goods
industry  spread  across the  entire  spectrum  of the metal  using  sector.  We
maintain a diverse  customer base with no significant  geographical  or customer
concentration.  Within  our core  specialty  metals  business  we believe we are
recognized as North America's leading  industrial  distributor of carbon,  alloy
and stainless steels; nickel alloy; aluminum; titanium; copper and brass as well
as an industry pioneer and premier provider of material management programs that
are designed to reduce our customer's total cost.

          Through our subsidiary Total Plastics, Inc. we also distribute a broad
range of value-added  industrial  plastics.  Together  Castle and our affiliated
companies operate in over 50 locations throughout North America.

                                       4




                                  RISK FACTORS

          You should carefully  consider the risks described below before making
a decision to invest in our common stock. The risks and uncertainties  described
below are examples only and are not the only ones that we face. Additional risks
and uncertainties that are not presently known to us or that we do not currently
believe are important to an investor may also harm our business  operations.  If
any of the events,  contingencies,  circumstances or conditions described in the
following risks actually occur, our business,  financial condition or results of
operations could be seriously harmed.  If that occurs,  the trading price of our
common stock could decline, and you may lose part or all of your investment.

          Our future operating  results depend on a number of factors beyond our
control  such as the prices for  metals,  which  could  cause our  results to be
adversely affected.

          The  prices we pay for raw  materials  and the  prices  we charge  for
products may change  depending  on many  factors not in our  control,  including
general  economic  conditions  (both domestic and  international),  competition,
production  levels,  import  duties and other trade  restrictions,  and currency
fluctuations.  To the extent metals prices  decline,  this generally  would mean
lower sales and possibly lower net income,  depending on the timing of the price
changes. To the extent we are not able to pass on to our customers any increases
in our  raw  materials  prices,  our  results  of  operations  may be  adversely
affected.

          We service  industries that are highly  cyclical,  and any downturn in
our customers' industries could reduce our revenue and profitability which could
result in a negative impact on our stock price.

          Many  of  our  products  are  sold  to  industries   that   experience
significant fluctuations in demand based on economic conditions,  energy prices,
consumer  demand  and  other  factors  beyond  our  control.  As a result of the
volatility in the  industries  we serve,  we may have  difficulty  increasing or
maintaining  our  level of sales of  profitability  if we are not able to divert
sales of our products to customers in other  industries  when one or more of our
customers' industries  experiencing a decline.  Therefore, we may not be able to
increase or maintain  its level of sales in periods of  economic  stagnation  or
downturn.


          The  success  of  our   business  is  affected  by  general   economic
conditions,  and,  accordingly,  our business has been and could  continue to be
adversely impacted by an economic slowdown or recession.

          Periods of economic slowdown or recession in the United States, or the
public  perception that one may occur, can decrease the demand for our products,
affect  the  availability  and cost of our  products  and  adversely  impact our
business.  The current  general  economic  slowdown has suppressed  activity and
demand in our industry over the past several  years.  This has been reflected in
our financial  losses in 2001 and 2002.  Our overall  financial  results in 2003
will be  substantially  dependent  upon the  extent to which  conditions  in our
industry and the general  economy  improve  during the  remainder of the year. A
prolonged  slowdown or slower than expected  recovery will adversely  affect our
business.

          Production time and the cost of our products could increase if we were
to lose one of our primary  suppliers,  which could adversely affect our ability
to meet our customer demands.

          If, for any reason,  our primary suppliers of metals should curtail or
discontinue their delivery of such raw materials to us in the quantities we need
and at prices that are competitive,  our business could suffer since we have few
long-term  contracts  to purchase  metals.  If, in the future,  we are unable to
obtain sufficient  amounts of the necessary raw materials at competitive  prices
and on a timely  basis  from our  traditional  suppliers,  we may not be able to
obtain such raw materials from alternative sources at competitive prices to meet
our delivery  schedules,  which could have an adverse impact on our revenues and
profitability.

          Our  industry is highly  competitive,  which may force us to lower our
prices thus causing an adverse affect on net income.

          The   principal   markets  that  we  serve  are  highly   competitive.
Competition  is  based  principally  on  price,  service,  quality,   production
capabilities, inventory availability and timely delivery. We compete in a highly
fragmented industry.  Competition in the various markets in which we participate
comes from a large number of value-added metals processors, service centers on a
regional and local basis, some of which have greater financial resources than we
do and some of which have more  established  brand names in the local markets we
serve.  We also compete to a lesser  extent with primary  metals  producers  who
typically sell to very large customers  requiring  shipments of large volumes of
metal.  Increased  competition  could  force us to lower our  prices or to offer
increased services at a higher costs to us, which could reduce our gross margins
and net income.

                                       5





          Ownership of our stock is  concentrated,  which may limit  stockholder
ability to influence corporate matters.

          Affiliates  and  family  members of one of our  directors,  Michael W.
Simpson,  collectively  control over  approximately 48% of our common stock (and
common  obtainable upon conversion of preferred  stock) through various estates,
partnerships,  corporations, trusts and individual ownership, including, without
limitation, shares owned by Mr. Simpson, and shares controlled by various trusts
for which our director,  Patrick J. Herbert, III, acts as trustee (collectively,
the "Related  Entities").  This  concentration  of ownership  retains the voting
power to  substantially  control the outcome of matters  requiring a stockholder
vote,  including  the  election of  directors  and the  approval of  significant
corporate  matters.  Such a concentration  of control could adversely affect the
market  price of our common  stock or prevent a change in control.  In addition,
the Related Entities, including without limitation, W.B. & Co. ("WB Co.") hold a
majority of the Company's outstanding Series A Cumulative  Convertible Preferred
Stock,  which gives the Related Entities the right, under the terms of the terms
of the Series A Cumulative  Convertible Preferred Stock, to restrict the Company
from taking certain actions, including amending its certificate of incorporation
or  bylaws  in a  manner  adverse  to the  rights  of the  Series  A  Cumulative
Convertible  Preferred  Stock,  paying or  declaring  dividends  on or redeeming
common  stock or issuing any capital  stock  senior in right of  liquidation  or
dividends to the Series A Cumulative  Convertible Preferred Stock. These consent
rights impose further  control upon the Company and may prevent the Company from
taking actions in the interest of the Common Stock.

          Trading volume of our stock is small which increases the volatility of
our stock price, which may have an adverse affect on stockholder's investment.

          Although a public market exists for our common stock, trading activity
has been  limited.  Due to the  relatively  small  number  of  shares  currently
outstanding,  the trading of a relatively  small number of shares could  subject
the stock price to volatility and  significantly  affect the market price of our
common  stock.  The market  price of our common stock is affected by a number of
other factors,  including variations in our operating results, evolving business
prospects and competitors,  as well as general conditions in the economy and the
financial   markets.   Also,  the  equity  markets  generally  have  experienced
significant price and volume fluctuations in recent years.

          We have  various  mechanisms  in place  that may  prevent  a change in
control that stockholders may otherwise consider favorable.

          In addition to the high  concentration of inside  ownership  described
above,  our certificate of  incorporation  and by-laws and the Maryland  General
Corporation  Law  include  provisions  that may be deemed  to have  antitakeover
effects and may delay,  defer or prevent a takeover  attempt  that  stockholders
might  consider  in their  best  interests.  Our  certificate  of  incorporation
contains  provisions that require the approval of two-thirds of the stockholders
entitled to vote to amend our certificate of incorporation  (unless our Board of
Directors has unanimously approved the amendment).  In addition, our by-laws may
be amended  only by our board of  directors,  and they contain  certain  advance
notice  procedures  for  nominating  candidates  for  election  to the  board of
directors.  Our board of directors is empowered to issue up to 10,000,000 shares
of  preferred  stock  and  to  determine  the  price,  rights,  preferences  and
privileges of such shares, without any further stockholder action. The existence
of this "blank-check" preferred stock could make more difficult or discourage an
attempt to obtain  control of the  Company by means of a tender  offer,  merger,
proxy contest or otherwise. In addition, this "blank check" preferred stock, and
an  issuance  thereof,  may have an adverse  effect on the  market  price of our
common stock. Furthermore,  we are subject to the antitakeover provisions of the
Maryland  General  Corporation Law that prohibit us from engaging in a "business
combination"  with an "interested  stockholder" for a period of five years after
the date of the  transaction  in which the person first  becomes an  "interested
stockholder,"  unless  the  business  combination  or  stockholder  interest  is
approved in a prescribed  manner.  The  application  of these and certain  other
provisions of the  certificate  of  incorporation  could also have the effect of
delaying or preventing a change of control of the Company, which could adversely
affect the market price of our common stock.

                                       6




                                 USE OF PROCEEDS

          We will not  receive  any of the  proceeds  from the sale of shares of
common stock covered by this prospectus. All of the proceeds will be received by
the Selling Stockholders.  A total of 1,793,722 of the shares offered hereby are
shares  obtainable  by  certain  Selling  Stockholders  upon  conversion  of all
outstanding  shares of our  Series A  Cumulative  Convertible  Preferred  Stock,
together with an additional 298,000 shares assuming the conversion of two years'
of accrued  dividends  at 8% per  annum.  The  Series A  Cumulative  Convertible
Preferred Stock has an aggregate  liquidation  preference  equal to $12,000,000,
and accrues dividends  (whether or not declared) at the per annum rate of 8%. To
the  extent  that the  Selling  Stockholders  convert  their  shares of Series A
Cumulative  Convertible  Preferred  Stock  into  shares  of  common  stock  sold
hereunder,  we will benefit from the elimination of the  liquidation  preference
and dividend obligation with respect to all shares so converted.

                               SELLING STOCKHOLDER

          We are  registering  shares of common stock for sale by those  persons
and entities identified in the table set forth below  (individually,  a "Selling
Stockholder" and collectively, the "Selling Stockholders").

          On November 22, 2002,  we issued a total of 12,000  shares of Series A
Cumulative Convertible Preferred Stock to a group of existing stockholders for a
total purchase price of $12,000,000 (the "Preferred Transaction").  The Series A
Cumulative  Convertible  Stock accrues a preferential  dividend at the per annum
rate of 8%. The Series A  Cumulative  Convertible  Preferred is  convertible  by
dividing the purchase  price  thereof  plus accrued  dividend by the  conversion
price of $6.69 per share. Of the shares offered hereby,  1,793,722 represent the
shares  issuable  upon  conversion  of  all  outstanding   Series  A  cumulative
Convertible Preferred,  and an additional 298,000 represent the conversion of an
assumed two years' of accrued  dividends.  Depending on the amount and timing of
conversion  and sale, the accrued  dividends and resulting  number of conversion
shares of common stock available for sale hereunder may be less.

          A total of 17,937 of the shares offered hereby represent shares issued
by us to William  Blair & Co., LLC in  consideration  for  services  rendered in
connection with the Preferred Transaction.

          The  remaining  700,336  shares  offered  hereby are held by the A. M.
Employee's  Trust,  U/T/A  12/28/50,  subtrust under the Master Trust  Agreement
between A. M. Castle & Co. and Northern  Trust  Company,  dated as of January 1,
1997,  which we refer to  herein as the  "Trust."  The Trust  will  receive  all
proceeds  from the share  offered  hereby under the A. M. Castle & Co.  Salaried
Employees  Pension Plan (the "Salaried  Plan") and the A. M. Castle & Co. Hourly
Employees  Retirement Plan (the "Hourly Plan" and collectively with the Salaried
Plan, the "Plans"), for the benefit of eligible participants under the Plans.

          The  following  table sets forth,  for each Selling  Stockholder,  the
number of shares  beneficially  owned by such Selling  Stockholder prior to this
offering,  the maximum  number of shares offered hereby and the number of shares
beneficially  owned by such Selling  Stockholder  after this offering,  assuming
that  all of the  shares  offered  hereby  are in  fact  sold  by  such  Selling
Stockholder.




              Selling Stockholder         Number of Shares       Number of Shares        Number of Shares    Percentage of
              -------------------          Owned Prior to          Being Offered(1)       After Offering      Class After
                                             Offering(1)           -------------          --------------       Offering
                                             --------                                                          --------
                                                                                                     
          A. M. Employee's Trust,           1,622,562                 700,336                 922,226            9.07%
          U/T/A 12/28/50, subtrust
          under the Master Trust
          Agreement between A. M.
          Castle & Co. and Northern
          Trust Company, dated as of
          January 1, 1997   (2)

          William Blair & Co., LLC            17,937                   17,937                     -0-             0.1%

          WB Co.                           6,167,326 (3)(4)         2,091,722 (4)           4,075,604           34.39%

                                                            7





          (1) The shares owned and offered hereby shall include, in addition to
the numbers indicated, any additional shares of our Common Stock that become
issuable by reason of any stock dividend, stock split, recapitalization or other
similar transaction effected without the receipt of consideration that results
in an increase in the number of outstanding shares of our Common Stock.

          (2) Of the shares held by the Trust, 1,210,067 are held by the Trust
on behalf of the Salaried Plan and 412,495 shares are held by the Trust on
behalf of the Hourly Plan. The trustee has responsibility to prudently manage
the common stock held by the Trust on behalf of each of the Plans a manner
consistent with maximizing the value of its investment in common stock and in
accordance with its determination of the extent to which it may prudently
continue to hold such shares consistent with the diversification and related
fiduciary requirements of ERISA. The trustee has the authority to cause the
Trust to sell shares of common stock on behalf of the Plans from time to time as
it may deem appropriate, and to vote the shares of common stock held by the
Trust on behalf of the Plans. The trustee intends to manage the sale of the
common stock in a manner consistent with maintaining an orderly market for the
shares. The Trustee intends to allocate sales of common stock between the Plans
in such manner as it deems to be in the best interests of each respective Plan.
The trustee has retained GreatBanc Trust Company to serve as its investment
advisor regarding the management and sale of the common stock offered hereby.
The compensation received by the trustee and its investment advisor is not
contingent in any way on the sale or continued ownership of common stock by the
Trust.

          (3)Holds no shares for its own benefit, 4,060,904 shares as nominee
for Simpson Estates, Inc. and the remainder as nominee for other individuals and
entities that are affiliates and/or family members of our director, Michael W.
Simpson. Such individuals and entities may hereafter offer the shares held by
them directly pursuant to the Plan of Distribution. However, WB Co. currently
maintains dispositive power over all shares offered hereby that are obtainable
upon conversion of the Preferred Stock. Several of such entities are trusts of
which our director, Patrick J Herbert, III, acts as trustee.

          (4)The shares owned and offered hereby assume that all 12,000
outstanding shares of its Series A Cumulative Convertible Preferred Stock is
ultimately convertible for (and is in fact converted into) the maximum number of
possible shares of Common Stock, and assumes 298,000 additional shares upon the
conversion of accrued dividends over two years.



                              PLAN OF DISTRIBUTION

          The Selling Stockholders are offering for resale under this prospectus
an  aggregate  of up to  2,809,995  shares  of our  common  stock.  The  Selling
Stockholders,  or their assignees and successors-in-interest may sell, from time
to time, any or all of the shares of common stock covered by this  prospectus on
any stock exchange, market or trading facility on which the shares are traded or
in private  transactions.  These sales may be at fixed or negotiated prices. The
Selling  Stockholders  may use any one or  more of the  following  methods  when
selling shares:

     o    Sales on the Chicago Stock Exchange or the American Stock Exchange, in
          the  over-the-counter  market or otherwise at prices and at terms then
          prevailing or at prices related to the then current market price;

     o    Underwritten offerings;

     o    Ordinary   brokerage   transactions  and  transactions  in  which  the
          broker-dealer solicits purchasers;

     o    Block  trades  in which the  broker-dealer  will  attempt  to sell the
          shares as agent but may  position and resell a portion of the block as
          principal to facilitate the transaction;

     o    Purchases  by  a   broker-dealer   as  principal  and  resale  by  the
          broker-dealer for its account;

     o    An  exchange   distribution  in  accordance  with  the  rules  of  the
          applicable exchange;

     o    Privately negotiated transactions;

     o    Short sales;

     o    Broker-dealers  may  agree  with the  Selling  Stockholders  to sell a
          specified number of such shares at a stipulated price per share;

                                       8




     o    A combination of any such methods of sale; or

     o    Any other method permitted pursuant to applicable law.

          The  Selling  Stockholders  may also  sell  shares  under  Rule 144 as
promulgated  under the Securities  Act of 1933, if available,  rather than under
this prospectus.

          The Selling  Stockholders  may, together with any agent of the Selling
Stockholders,  accept or reject in whole or in part any proposed purchase of the
shares of common  stock  offered by this  prospectus.  We will not  receive  any
proceeds from the offering of shares by the Selling Stockholders.

          Under applicable rules and regulations  under the Securities  Exchange
Act of 1934, any person engaged in a distribution  of the shares of common stock
covered by this  prospectus  may be  limited in its  ability to engage in market
activities with respect to such shares. The Selling  Stockholders,  for example,
will be subject to applicable  provisions of the Securities Exchange Act of 1934
and  the  rules  and  regulations  under  it,  including,   without  limitation,
Regulation  M,  which   provisions  may  restrict   activities  of  the  Selling
Stockholders and limit the timing of purchases and sales of any shares of common
stock by the Selling  Stockholder.  Furthermore,  under  Regulation  M,  persons
engaged in a  distribution  of securities  are  prohibited  from  simultaneously
engaging in market making and other  activities  with respect to such securities
for a specified period of time prior to the commencement of such  distributions,
subject to specified  exceptions  or  exemptions.  The  foregoing may affect the
marketability of the shares offered by this prospectus.

          The Selling  Stockholders  may also engage in short sales  against the
box (where the seller  actually  owns the stock,  but does not want to close out
the position,  but instead sells a put option covered by the retained position),
puts (an option giving the holder of the option the right to sell the stock at a
given  price by a given  date) and calls  (the  opposite  of a put, a call is an
option  that gives the holder the right to buy stock at a given price in a given
period of time) and other  transactions  in our securities or derivatives of our
securities and may sell or deliver shares in connection  with these trades.  The
Selling  Stockholders  may  pledge  their  shares to  brokers  under the  margin
provisions  of customer  agreements or other lenders under the terms of the loan
agreements.  If the Selling Stockholders default on a margin loan or other loan,
the broker or lender may offer and sell, from time to time, the pledged shares.

          The Selling  Stockholders  may sell shares  directly to market  makers
acting as principals  and/or  broker-dealers  acting as agents for themselves or
their customers.  Broker-dealers engaged by the Selling Stockholders may arrange
for other  broker-dealers  to participate in sales.  Broker-dealers  may receive
commissions,  concessions or discounts from the Selling Stockholders (or, if any
broker-dealer acts as agent for the purchaser of shares,  from the purchaser) in
amounts  to  be  negotiated.  The  Selling  Stockholders  do  not  expect  these
commissions  and  discounts  to  exceed  what  is  customary  in  the  types  of
transactions  involved.  Market  makers and block  purchasers  that purchase the
shares will do so for their own  account  and at their own risk.  It is possible
that the Selling  Stockholders will attempt to sell shares in block transactions
to market makers or other  purchasers at a price per share that may be below the
then-current  market  price.  We cannot make  assurances  that all or any of the
shares of common stock will be sold by the Selling Stockholders.

          The Selling  Stockholders  and any  broker-dealers  or agents that are
involved  in  selling  the shares  may be deemed to be  underwriters  within the
meaning of the  Securities  Act of 1933 in connection  with such sales.  In such
event, any commissions  received by such broker-dealers or agents and any profit
on the resale of the shares  purchased by them may be deemed to be  underwriting
commissions or discounts under the Securities Act of 1933.

          We have not registered or qualified the shares of common stock offered
by this prospectus under the laws of any country,  state or jurisdiction,  other
than the United States.

          Certain of the  Selling  Stockholders  have agreed to  indemnify  such
broker-dealers  with  respect  to the  shares  offered  hereby  against  certain
liabilities,   including  certain  liabilities  under  the  Securities  Act.  In
addition,  the Company has agreed to indemnify  such Selling  Stockholders  with
respect to the shares  offered  hereby against  certain  liabilities,  including
certain   liabilities  under  the  Securities  Act  or,  if  such  indemnify  is
unavailable, to contribute toward amounts required to be paid in respect of such
liabilities.

          The  Company  will  pay  the  registration  expenses  incident  to the
offering and sale of the shares by the Selling  Stockholders to the public. Such
expenses (estimated to be $15,000) include legal and accounting expenses, filing
fees  payable to the  Commission,  applicable  state  "blue sky" filing fees and
printing  expenses.  The  Company,  however,  will  not pay  for  any  expenses,
commissions  or  discounts  of  underwriters,  dealers  or agents for any of the
Selling Stockholders.

                                       9




          Our common stock is currently traded on the Chicago Stock Exchange and
the American Stock  Exchange.  The public offering price for any shares that are
sold will be determined  by the price  indicated on such system at the time such
sale  occurs,  or  at  such  price  as  shall  be  determined   through  private
negotiations between the buyers and the Selling Stockholders, or their agents.


                                VALIDITY OF STOCK

          Jerry M. Aufox,  Secretary and Corporate  Counsel of A.M. Castle,  has
issued an  opinion  about the  validity  of the shares of common  stock  offered
hereby. Mr. Aufox is the beneficial owner of 22,422 shares of common stock.


                                     EXPERTS

          The financial  statements and the related financial statement schedule
incorporated in this prospectus by reference from our Annual Report on Form 10-K
for the year ended December 31, 2002 have been audited by Deloitte & Touche LLP,
independent  auditors,  as stated in their  report  (which  report  expresses an
unqualified  opinion  and  includes  an  explanatory  paragraph  relating to the
Company's change in its method of accounting for goodwill and intangible  assets
upon adoption of Statement of Financial  Accounting Standards No. 142, "Goodwill
and Other Intangible  Assets"),  which is incorporated herein by reference,  and
have been so  incorporated  in reliance  upon the report of such firm given upon
their authority as experts in accounting and auditing.

                                       10




                                    PART II

                     INFORMATION NOT REQUIRED IN PROSPECTUS

Item 14.  Other Expenses of Issuance and Distribution.

     The  following  table  sets forth the costs and  expenses  payable by us in
connection with the sale of our common stock being  registered  hereby.  All the
amounts  shown  are  estimated,   except  the  Securities   Exchange  Commission
registration fee.

              SEC registration fee........................$1,136.64

              Printing expenses.................................500

              Legal fees and expenses.........................5,000

              Accounting fees and expenses....................5,000

              Miscellaneous expenses.......................3,363.36

                              Total                       $  15,000


Item 15.  Indemnification of Directors and Officers.

          We  are  a   Maryland   corporation,   subject   to   the   applicable
indemnification  provisions  of the  General  Corporation  Law of the  State  of
Maryland (the "MGCL"). Section 2-418 of the MGCL empowers a Maryland corporation
to indemnify,  subject to certain prescribed standards, any person in connection
with any action, suit or proceeding brought or threatened because such person is
or was a director,  officer, employee or agent of the corporation or was serving
as such with  respect to another  corporation  or other entity at the request of
such corporation.

          Section 2-405.2 of the MGCL permits a Maryland  corporation to include
in its  certificate  of  incorporation  a  provision  eliminating  or limiting a
director's  liability to a corporation or its stockholders for money damages.  A
Maryland  corporation  may  indemnify  its  present  and  former  directors  and
officers,  among others,  against (1) judgments,  (2) penalties,  (3) fines, (4)
settlements and (5) reasonable  expenses actually incurred by them in connection
with any proceeding to which they may be made a party by reason of their service
in those or other capacities.

          The MGCL does not permit a  corporation  to indemnify  its present and
former directors, officers, agents or employees if it is established that:

   o  the act or  omission  of the  director,  officer,  employee  or agent  was
      material to the matter giving rise to the  proceeding and was committed in
      bad faith or was the result of active and deliberate dishonesty;

   o  the director,  officer,  employee or agent  actually  received an improper
      personal benefit in money, property or services; or

   o  in the case of any criminal proceeding, the director, officer, employee or
      agent  had  reasonable  cause  to  believe  that the act or  omission  was
      unlawful.

          Unless a corporation's  charter provides otherwise,  which our charter
does not, the MGCL requires a corporation to indemnify a director or officer who
has  been  successful,  on  the  merits  or  otherwise,  in the  defense  of any
proceeding  to  which  he is made a  party  by  reason  of his  service  in that
capacity.




          Under the MGCL, a Maryland  corporation  generally may not indemnify a
person for an adverse  judgment in a suit by or in the right of the corporation.
Also, a Maryland corporation generally may not indemnify a person for a judgment
of liability on the basis that  personal  benefit was  improperly  received.  In
either of these  cases,  a  Maryland  corporation  may  indemnify  a person  for
expenses  only if a court so orders.  Our bylaws  obligate us to  indemnify  our
directors and officers, whether serving us or, at our request, any other entity,
to the  maximum  extent  required  or  permitted  by  the  MGCL,  including  the
advancement of expenses under the procedures and to the maximum extent permitted
by law.

          Our charter also  contains  provisions  that  eliminate  and limit the
personal  liability  of  directors  to the full  extent  permitted  by the MGCL.
Pursuant to the MGCL, our charter also limits the personal liability of officers
to the same  extent  as  directors.  Under  the  MGCL,  limitation  of  personal
liability of directors  or officers is  permitted in all but the  following  two
situations:  (1) for the amount of any improper benefit they actually receive or
(2) to the extent that a judgment or final adjudication  adverse to the director
or officer in a  proceeding  based on the  finding in that  proceeding  that the
person's  action,  or  failure to act,  was the result of active and  deliberate
dishonesty  and  was  material  to  the  cause  of  action  adjudicated  in  the
proceeding.

          We may maintain  insurance,  at our expense,  to protect us and any of
our   directors,   officers,   employees  or  agents  or  another   corporation,
partnership,  joint  venture,  trust or other  enterprise  against any  expense,
liability  or loss,  whether  or not we would have the power to  indemnify  such
person against expense, liability or loss under the MGCL.

Item 16.  Exhibits.

     (a) Exhibits (all filed herewith except where otherwise noted):

               3.1  Articles of Incorporation (1)
               3.2  Bylaws (1)
               4.1  Series A Cumulative  Convertible  Preferred  Stock  Purchase
                    Agreement, dated November 22, 2002 (2)
               4.2  Articles   Supplementary--Series  A  Cumulative  Convertible
                    Preferred Stock (2)
               4.3  Registration Rights Agreement, dated November 22, 2002 (2)
               5.1  Opinion of Jerry M. Aufox,  General  Counsel,  regarding the
                    legality of the securities being registered
               23.1 Consent of Deloitte & Touche LLP, independent auditors
               23.2 Consent of Jerry M. Aufox (included in Exhibit 5.1)
               24   Powers of Attorney (page II-4)

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

(1)  Incorporated  by reference to the Company's  Definitive  Proxy Statement on
     Form 14A filed on Mrch 15, 2002.

(2)  Incorporated by reference to Item 7 to the Company's Current Report on Form
     8K filed on December 2, 2002.


Item 17.  Undertakings.

     (a)  The undersigned Registrant hereby undertakes:

          (1) To file,  during  any  period  in which  offers or sales are being
     made, a post-effective amendment to this registration statement:

               (i) To include any prospectus required by section 10(a)(3) of the
          Securities Act of 1933;

               (ii) To reflect  in the  prospectus  any facts or events  arising
          after the effective  date of the  registration  statement (or the most
          recent post-effective amendment thereof) which, individually or in the
          aggregate, represent a fundamental change in the information set forth
          in the  registration  statement.  Notwithstanding  the foregoing,  any




          increase  or decrease  in volume of  securities  offered (if the total
          dollar  value of  securities  offered  would not exceed that which was
          registered)  and  any  deviation  from  the  low  or  high  end of the
          estimated  maximum  offering  range  may be  reflected  in the form of
          prospectus filed with the Securities and Exchange  Commission pursuant
          to Rule 424(b) under the  Securities  Act of 1933, as amended,  if, in
          the aggregate,  the changes in volume and price represent no more than
          a 20% change in the maximum aggregate  offering price set forth in the
          "Calculation of Registration Fee" table in the registration statement;

               (iii) To include any  material  information  with  respect to the
          plan of  distribution  not  previously  disclosed in the  registration
          statement  or  any  material   change  to  such   information  in  the
          registration statement;

               Provided,  however,  that paragraphs  (a)(1)(i) and (a)(1)(ii) do
          not  apply  if  the   information   required   to  be  included  in  a
          post-effective  amendment by those paragraphs is contained in periodic
          reports filed with or furnished to the  Commission  by the  Registrant
          pursuant to Section 13 or Section 15(d) of the Securities Exchange Act
          of  1934  that  are  incorporated  by  reference  in the  registration
          statement.

          (2) That,  for the  purpose of  determining  any  liability  under the
     Securities Act of 1933, each such post-effective  amendment shall be deemed
     to be a new  registration  statement  relating  to the  securities  offered
     therein,  and the offering of such  securities at that time shall be deemed
     to be the initial bona fide offering thereof.

          (3) To remove from registration by means of a post-effective amendment
     any  of  the  securities  being  registered  which  remain  unsold  at  the
     termination of the offering.

     (b) The  undersigned  Registrant  hereby  undertakes  that, for purposes of
determining  any liability  under the Securities Act of 1933, each filing of the
Registrant's  annual  report  pursuant to Section  13(a) or Section 15(d) of the
Securities  Exchange Act of 1934, as amended,  that is incorporated by reference
in the registration statement shall be deemed to be a new registration statement
relating to the securities offered therein,  and the offering of such securities
at that time shall be deemed to be the initial bona fide offering thereof.

     (c) Insofar as indemnification for liabilities arising under the Securities
Act of 1933, as amended, may be permitted to directors, officers and controlling
persons of the Registrant  pursuant to the foregoing  provisions,  or otherwise,
the  Registrant  has been  advised  that in the  opinion of the  Securities  and
Exchange  Commission such  indemnification is against public policy as expressed
in the Securities Act of 1933, as amended, and is, therefore,  unenforceable. In
the event that a claim for the  indemnification  against such liabilities (other
than the payment by the  Registrant of expenses  incurred or paid by a director,
officer or controlling person of the Registrant in the successful defense of any
action, suit or proceeding) is asserted by such director, officer or controlling
person in connection with the securities being registered,  the Registrant will,
unless in the opinion of its counsel the matter has been settled by  controlling
precedent,  submit to a court of appropriate  jurisdiction  the question whether
such  indemnification  by it is  against  public  policy  as  expressed  in  the
Securities Act and will be governed by the final adjudication of such issue.






                                   SIGNATURES

          Pursuant  to the  requirements  of the  Securities  Act  of  1933,  as
amended, the Registrant certifies that it has reasonable grounds to believe that
it meets all of the requirements for filing on Form S-3 and has duly caused this
Registration Statement to be signed on its behalf by the undersigned,  thereunto
duly  authorized,  in the City of Franklin Park,  State of Illinois,  on July 1,
2003.

                                            A. M. CASTLE & CO.

                                            BY:  /s/
                                               --------------------------------
                                                      G. Thomas McKane
                                                      President &
                                                      Chief Executive Officer

          The  undersigned  officers and  directors of A. M. Castle & Co. hereby
severally  constitute and appoint G. Thomas McKane and Jerry M. Aufox,  and each
of them, our true and lawful attorneys and agents,  with full power, to sign for
us  and  in our  names  in the  capacities  indicated  below,  the  Registration
Statement  on  Form  S-3  filed  herewith  and any  and  all  pre-effective  and
post-effective  amendments to said Registration  Statement,  and generally to do
all such things in our names and on our behalf in our capacities as officers and
directors  to enable A. M.  Castle & Co. to comply  with the  provisions  of the
Securities Act of 1933, as amended,  and all  requirements of the Securities and
Exchange Commission,  hereby ratifying and confirming our signatures as they may
be signed by our said attorneys,  to said Registration Statement and any and all
amendments thereto.



          PURSUANT  TO THE  REQUIREMENTS  OF THE  SECURITIES  ACT  OF  1933,  AS
AMENDED,  THIS  REGISTRATION  STATEMENT HAS BEEN SIGNED BELOW BY OR ON BEHALF OF
THE FOLLOWING PERSONS IN THE CAPACITIES AND ON THE DATES INDICATED.

         Signature                                   Title                                Date
         ---------                                   -----                                ----
                                                                                 
/s/  G. THOMAS MCKANE             President & Chief Executive Officer (Principal       July 1, 2003
-----------------------------          Executive Officer) and Director
     G. Thomas McKane

/s/  EDWARD F. CULLITON                     Principal Financial and                    July 1, 2003
-----------------------------           Accounting Officer and Director
     Edward F. Culliton

/s/  ROBERT W. GRUBBS                               Director                           July 1, 2003
-----------------------------
     Robert W. Grubbs

/s/  WILLIAM K. HALL                                Director                           July 1, 2003
-----------------------------
     William K. Hall

/s/  ROBERT S. HAMADA                               Director                           July 1, 2003
-----------------------------
     Robert S. Hamada

/s/  PATRICK J. HERBERT, III                        Director                           July 1, 2003
-----------------------------
     Patrick J. Herbert, III

/s/  JOHN P. KELLER                                 Director                           July 1, 2003
-----------------------------
     John P. Keller

/s/  JOHN W. MCCARTER, JR.                          Director                           July 1, 2003
-----------------------------
     John W. McCarter, Jr.

/s/  JOHN MCCARTNEY                                 Director                           July 1, 2003
-----------------------------
     John McCartney

/s/  JOHN W. PUTH                                   Director                           July 1, 2003
-----------------------------
     John W. Puth

/s/  MICHAEL SIMPSON                                Director                           July 1, 2003
-----------------------------
     Michael Simpson