JOINDER AGREEMENT AND
                          AMENDMENT TO CREDIT AGREEMENT

         This Joinder  Agreement and Amendment to Credit Agreement (the "Joinder
Agreement") is made and entered into as of December 31, 2000, by and among:

     (1) Commonwealth Industries, Inc., a corporation duly organized and validly
existing  under  the  laws of the  State  of  Delaware  (the  "Parent")  and the
successor by merger to CI Holdings, Inc.;

     (2) CA Lewisport,  Inc., a corporation  duly organized and validly existing
under the laws of the  State of  Delaware  and  formerly  known as  Commonwealth
Aluminum  Lewisport,  Inc.,  and  as  Commonwealth  Aluminum  Corporation  ("Old
Lewisport");

     (3) CI Holdings,  Inc., a corporation  duly organized and validly  existing
under the laws of the State of Delaware and formerly known as Alflex Corporation
("CI Holdings");

     (4) Commonwealth  Aluminum Concast,  Inc., a corporation duly organized and
validly existing under the laws of the State of Ohio ("CACI");

     (5)  Commonwealth  Aluminum  Corporation,  a corporation duly organized and
validly  existing under the laws of the State of Delaware  ("CAC";  each of CAC,
CACI,  Old  Lewisport  and CI Holdings is sometimes  hereafter  referred to as a
"Borrower" and collectively as the "Borrowers");

     (6) The  Subsidiaries of the Parent  identified by the caption  "Subsidiary
Guarantors" on the signature pages hereto (the "Subsidiary Guarantors");

     (7) Alflex  Corporation,  a corporation duly organized and validly existing
under the laws of the State of Delaware ("New Alflex");

     (8) Commonwealth Aluminum Lewisport,  LLC, a limited liability company duly
formed  and  validly  existing  under  the laws of the State of  Delaware  ("New
Lewisport");

     (9) Commonwealth  Aluminum Metals,  LLC, a limited  liability  company duly
formed and validly  existing under the laws of the State of Delaware  ("Metals";
together with New Alflex and New Lewisport,  the "New Borrowers";  and, together
with the Parent, the Subsidiary Guarantors and the Borrowers, the "Obligors");

     (10) Bank One, Indiana,  NA, for itself and as administrative agent for the
Lenders (as hereafter defined) (the "Administrative Agent");

     (11) PNC Bank, National Association ("PNC");

     (12) ABN AMRO Bank N.V. ("ABN AMRO");

     (13) Bank of Montreal ("Montreal");

     (14) Credit Agricole Indosuez ("Indosuez");

     (15) Mellon Bank, N.A. ("Mellon Bank");

     (16) The Industrial Bank of Japan, Limited ("IBJ"); and

     (17) Firstar  Bank,  NA ("Firstar"  and,  together with the  Administrative
Agent, PNC, ABN AMRO, Montreal, Indosuez, Mellon Bank, and IBJ, the "Lenders").

                             PRELIMINARY STATEMENTS:

A. Parent, each of the Borrowers,  each of the Subsidiary Guarantors and each of
the  Lenders  are  parties  to a certain  Second  Amended  and  Restated  Credit
Agreement dated as of December 19, 1997, as amended by Amendment No. 1 to Credit
Agreement dated December 22, 1998, an Agreement of Resignation,  Appointment and
Acceptance  dated August 18, 1999, a Joinder  Agreement  dated as of October 29,
1999, a Joinder  Agreement dated as of December 31, 1999, and a letter agreement
dated as of  December  27,  2000 (as  amended  from  time to time,  the  "Credit
Agreement").

B. Parent,  each of the  Borrowers,  each of the  Subsidiary  Guarantors and the
Administrative  Agent (as successor to National Westminster Bank PLC pursuant to
the Agreement of Resignation,  Appointment and Acceptance dated August 18, 1999)
are parties to a certain  Amended and  Restated  Pledge and  Security  Agreement
dated as of  November  29,  1996,  as  amended  by  Amendment  No. 1 dated as of
December 19, 1997, by a Joinder Agreement dated as of October 29, 1999, and by a
Joinder  Agreement  dated as of  December  31,  1999 (as  amended,  the  "Pledge
Agreement").

     C. Certain of the Obligors have caused the formation of the New  Borrowers,
and the  Borrowers  have  requested  that the  Lenders  agree  to allow  the New
Borrowers to join as Borrowers under the Credit Agreement.

     D. Each of Old Lewisport and CI Holdings has changed its name, and each has
requested that the Lenders consent to such change of name.

     E. The Obligors have requested that the Lenders  restate their agreement to
amend Section 9.10(b) of the Credit Agreement in certain respects.

                  NOW THEREFORE,  the parties hereto,  in consideration of their
mutual  covenants  and  agreements  hereinafter  set forth and  intending  to be
legally bound hereby, covenant and agree as follows:

1.  Joinder.  Each  of the New  Borrowers  hereby  executes  and  delivers  this
Agreement  to the  Lenders,  pursuant  to  which  each New  Borrower  joins as a
"Borrower"  (as  defined  in the Credit  Agreement),  and  becomes  liable as an
Borrower  under,  each of the  documents  to which  the  Borrowers  are  parties
(including without limitation the Credit Agreement, each of the Revolving Credit
Notes,  each of the  Swingline  Notes,  and the Pledge  Agreement),  jointly and
severally  liable  with all  other  Borrowers  under  and with  respect  to such
documents.  Each of the other  Borrowers  consents to the joinder of each of the
New Borrowers.

         2. Consent of Lenders.  Each of the Lenders  hereby (i) consents to the
change of Old Lewisport's name from "Commonwealth Aluminum Lewisport,  Inc.," to
"CA  Lewisport,  Inc.," (ii)  consents to the change of CI  Holdings'  name from
"Alflex Corporation" to "CI Holdings,  Inc.," and (iii) consents to the addition
of each of the New Borrowers as, and agrees that each of the New Borrowers shall
be, a "Borrower"  under the Credit  Agreement,  the Revolving  Credit Notes, the
Swingline  Notes,  the Pledge Agreement and each of the other documents to which
the Borrowers are parties.

     3. Amendment to Section 9.10(b). Section 9.10(b) of the Credit Agreement is
hereby  modified and amended so that, as modified and amended,  it shall read in
its entirety as follows:

                  "(b)     Interest Coverage Ratio.
                           -----------------------

                           The  Parent  will  not  permit  the  Total   Interest
                  Coverage Ratio to be less than the following respective ratios
                  at any time during the following respective periods:

                  Period                                           Ratio

                  From the Restatement Effective Date
                   through December 30, 1998                    2.00 to 1.00

                  From December 31, 1998
                   through September 29, 1999                   2.25 to 1.00

                  From September 30, 1999
                   through December 30, 1999                    2.50 to 1.00

                  From December 31, 1999
                   through December 30, 2000                    3.00 to 1.00

                  From December 31, 2000
                   through December 30, 2001                    2.75 to 1.00

                  From December 31, 2001
                   and at all times thereafter                  3.00 to 1.00"

         4. Affirmation of Representations and Warranties.  Each of the Obligors
(including  each of the New Borrowers)  hereby affirms that the  representations
and warranties contained in the Credit Agreement and in the Pledge Agreement are
true and accurate as of the  Effective  Date and as of the date of the execution
and delivery of this Joinder  Agreement.  Each further  represents  and warrants
that each has the power to enter into and perform  this Joinder  Agreement.  The
making and performance by the Obligors  (including each of the New Borrowers) of
this Joinder Agreement has been duly authorized by all necessary action and will
not:

     (i) violate any provision of law or of any of the Obligors'  (including the
New Borrowers') certificates of incorporation or formation, or bylaws or limited
liability company agreements,

     (ii) result in the breach of, or constitute a default under,  any agreement
or instrument to which any of the Obligors  (including  the New  Borrowers) is a
party or by which any of the Obligors  (including  the New  Borrowers) or any of
their respective property may be bound or affected, or

     (iii) result in the creation of any lien,  charge or  encumbrance  upon any
property or assets of any of the Obligors (including the New Borrowers),  except
as provided by this Joinder Agreement (in the case of the New Borrowers).

No consent, approval, authorization,  declaration, exemption or other action by,
or notice to, any court or governmental or administrative  agency or tribunal is
or will be required in connection  with the  execution,  delivery,  performance,
validity  or  enforcement  of this  Joinder  Agreement  or any other  agreement,
instrument or document to be executed and delivered pursuant hereto.

         5. No  Impairment  and  Ratification.  Each  Guarantor  consents to the
entering  into of this  Joinder  Agreement by each of the  Borrowers,  the other
Guarantors and the New Borrowers.  Each of the Obligors agrees that neither this
Joinder  Agreement  nor anything  contained  herein or in any other  document or
instrument  delivered  in  connection  herewith  shall  diminish  or impair  any
Guarantor's liability in any respect under its Guaranty.  Each Guarantor further
agrees that its  Guaranty  is, by the  execution  and  delivery of this  Joinder
Agreement,  ratified, confirmed and reaffirmed in its entirety, and acknowledged
to continue in full force and effect.

         6. Ratification. Except as expressly amended by this Joinder Agreement,
the Credit  Agreement,  the Pledge Agreement and the Guaranties are and shall be
unchanged.  All of the terms,  provisions,  covenants,  agreements,  conditions,
schedules  and  exhibits  thereof or thereto  shall  remain and continue in full
force and effect and are hereby incorporated by reference,  and hereby ratified,
reaffirmed  and confirmed by the Obligors  (including the New Borrowers) and the
Lenders  in all  respects  on  and as of the  effective  date  of  this  Joinder
Agreement.  Each of the Obligors (including the New Borrowers)  acknowledges and
agrees that all liens,  security interests,  and pledges heretofore given to the
Lenders to secure their respective indebtedness to the Lenders shall also secure
all obligations arising hereunder.

     7.  Conditions.  The  Lenders'  agreements  and  consents  in this  Joinder
Agreement  are and shall be subject to the prior  satisfaction  of the following
conditions precedent:

     (a) Execution and Delivery of this Joinder Agreement. All of the parties to
this Joinder Agreement shall have executed and delivered a counterpart hereof.

     (b) Evidence of Existence and Authorization. The Administrative Agent shall
have received the following:

     (i) for each of the New  Borrowers,  a copy of charter  documents,  limited
liability  company  agreement and  resolutions  relating to such New  Borrower's
execution and delivery of this Joinder Agreement, all certified as true, correct
and complete by a member or manager of such New Borrower; and

     (ii) for all Obligors,  copies of resolutions relating to the execution and
delivery of this Joinder Agreement,  all certified as true, correct and complete
by the Secretary or an Assistant Secretary of each Obligor.

                  (c) Chattel Search  Results.  The  Administrative  Agent shall
have   received   such  legal   opinions,   UCC-11   Reports  or  reports   from
nationally-recognized  chattel search firms and similar  information  reflecting
that the security interests granted to the Administrative Agent, for the benefit
of the  Lenders,  by each of the New  Borrowers  are first  and prior  perfected
security interests.

     (d) Legal Opinions.  The Administrative Agent shall have received the legal
opinions of the law firms of:

     (i)  Sullivan & Cromwell,  substantially  in the form of Exhibit A attached
hereto and incorporated herein by this reference,

     (ii) Womble, Carlisle, Sandridge & Rice, PLLC, substantially in the form of
Exhibit B attached hereto and incorporated herein by this reference,

     (iii)  Taft,  Stettenius  &  Hollister  LLP,  substantially  in the form of
Exhibit C attached hereto and incorporated herein by this reference,

     (iv)  Morrison  &  Foerster,  LLP,  substantially  in the form of Exhibit D
attached hereto and incorporated herein by this reference

     (v) Wyatt,  Tarrant & Combs,  LLP,  substantially  in the form of Exhibit E
attached hereto and incorporated herein by this reference

     (e)  Financing  Statements.   All  UCC-1  financing  statements  and  other
documents, duly executed, as the Administrative Agent determines to be necessary
to perfect  the  security  interests  intended  to be granted by each of the New
Borrowers under the Pledge  Agreement and to reflect the changes of the names of
CI Holdings and Old Lewisport.

     (f) Proceedings Satisfactory.  All proceedings taken in connection with the
transactions  contemplated herein shall be satisfactory to the Lenders and their
counsel.  The  Lenders  and their  counsel  shall have  received  copies of such
documents as they may request in connection therewith, all in form and substance
satisfactory to the Lenders and their counsel.

         8.       General Provisions.
                  ------------------

(a) Entire Agreement. This Agreement, the Credit Agreement, the Pledge Agreement
and the other documents to which the Obligors  (including the New Borrowers) are
parties pursuant to the Credit Agreement  constitute the entire agreement of the
parties  with  respect to the  subject  matter  hereof and  thereof.  No change,
modification,  addition or termination  of this  Agreement  shall be enforceable
unless in writing and signed by the party against whom enforcement is sought.

(b) Definitions.  Terms used and not otherwise defined in this Joinder Agreement
shall have the meanings given to them in the Credit  Agreement,  as amended from
time to time.

(c) Benefit.  This Agreement  shall be binding upon the Obligors,  including the
New Borrowers,  and their  respective  successors and assigns and shall inure to
the benefit of the Lenders and their respective successors and assigns.

(d) Waiver.  No waiver of the  provisions  hereof shall be  effective  unless in
writing and signed by the party to be charged with such waiver.  No waiver shall
be deemed a  continuing  waiver or a waiver in respect of any breach or default,
whether  of a similar  or a  different  nature,  unless  expressly  so stated in
writing.

     (e)  Governing  Law.  The  validity,   construction,   interpretation   and
enforcement of this Agreement  shall be construed in accordance with the laws of
the State of New York without regard to its conflict of laws.

(f) Severability. If any provision of this Agreement or its application shall be
deemed  invalid,   illegal  or  unenforceable  in  any  respect,  the  validity,
construction,  interpretation  and  enforceability of all other  applications of
that provision and of all other provisions and applications  hereof shall not in
any way be affected or impaired.

(g) Further Assurances. From time to time at another party's request and without
further  consideration,  the parties  shall  execute and  deliver  such  further
instruments  and documents,  and take such other action as the requesting  party
may reasonably  request,  in order to complete more effectively the transactions
contemplated in this Agreement.

                  (h) Counterparts. This Agreement may be executed in any number
of  counterparts,  each of which shall be deemed an  original,  but all of which
together  shall  constitute  one and the same  agreement.  This Agreement may be
executed by each party on separate copies,  which copies, when combined so as to
include the signatures of all parties,  shall constitute a single counterpart of
this Agreement.

                  (i) Letter  Agreement.  This  Agreement  amends,  restates and
supersedes  that certain letter  agreement dated as of December 27, 2000, by and
among the Lenders and the Borrowers, which letter agreement is hereby terminated
and of no further force or effect.



         IN WITNESS  WHEREOF,  the parties hereto,  by their officers  thereunto
duly authorized, have executed this Agreement,  effective as of the date set out
in the preamble of this Agreement.

"Parent"                   Commonwealth Industries, Inc.

                         By:
                         ------------------------------------------------------
                         Title:
                         ------------------------------------------------------

"Borrowers"                CA Lewisport, Inc.

                         By:
                         ------------------------------------------------------
                         Title:
                         ------------------------------------------------------

                           CI Holdings, Inc.

                         By:
                         ------------------------------------------------------
                         Title:
                         ------------------------------------------------------

                           Commonwealth Aluminum Concast, Inc.

                         By:
                         ------------------------------------------------------
                         Title:
                         ------------------------------------------------------

                           Commonwealth Aluminum Corporation

                         By:
                         ------------------------------------------------------
                         Title:
                         ------------------------------------------------------

"Subsidiary Guarantors"    Commonwealth Aluminum Sales Corporation

                         By:
                         ------------------------------------------------------
                         Title:
                         ------------------------------------------------------

                           Alflex E1 LLC,  by its sole
                           member, CI Holdings, Inc.

                         By:
                         ------------------------------------------------------
                         Title:
                         ------------------------------------------------------


"New Borrowers"            Alflex Corporation

                          By:
                          -----------------------------------------------------
                          Title:
                          -----------------------------------------------------

                           Commonwealth Aluminum Lewisport, LLC

                          By:
                          -----------------------------------------------------
                          Title:
                          -----------------------------------------------------

                            Commonwealth Aluminum Metals, LLC

                          By:
                          -----------------------------------------------------
                          Title:
                          -----------------------------------------------------

"Lenders"                   Bank One, Indiana, NA

                          By:
                          -----------------------------------------------------
                          Title:
                          -----------------------------------------------------

                            PNC Bank, National Association

                          By:
                          -----------------------------------------------------
                          Title:
                          -----------------------------------------------------

                            ABN AMRO Bank N.V.

                          By:
                          -----------------------------------------------------
                          Title:
                          -----------------------------------------------------

                            Bank of Montreal

                          By:
                          -----------------------------------------------------
                          Title:
                          -----------------------------------------------------

                            Credit Agricole Indosuez

                          By:
                          -----------------------------------------------------
                          Title:
                          -----------------------------------------------------

                            Mellon Bank, N.A.

                          By:
                          -----------------------------------------------------
                          Title:
                          -----------------------------------------------------



                            The Industrial Bank of Japan, Limited

                          By:
                          -----------------------------------------------------
                          Title:
                          -----------------------------------------------------

                            Firstar Bank, NA

                          By:
                          -----------------------------------------------------
                          Title:
                          -----------------------------------------------------