TAX AGREEMENT
                                     BETWEEN
                               NL INDUSTRIES, INC.
                                       AND
                            COMPX INTERNATIONAL INC.

     This  Agreement is executed on October 5, 2004 but  effective as of October
1, 2004 by and among NL Industries,  Inc. ("NL"), a Delaware  corporation having
its principal executive offices at Three Lincoln Centre, 5430 LBJ Freeway, Suite
1700,  Dallas,  Texas  75240,  Contran  Corporation   ("Contran"),   a  Delaware
corporation having its principal executive offices at Three Lincoln Centre, 5430
LBJ  Freeway,  Suite  1700,  Dallas,  Texas 75240 and CompX  International  Inc.
("CompX"),  a Delaware  corporation  having its principal  executive  offices at
Three Lincoln Centre, 5430 LBJ Freeway, Suite 1700, Dallas, Texas 75240.

                                    Recitals

     A. NL and CompX are eligible to file consolidated returns of federal income
taxes and, subject to certain jurisdictional limitations, will be subject to, or
continue  to be subject to,  combined  state and local tax  reporting  effective
October 1, 2004.

     B. NL and CompX wish to provide  for the  allocation  of  liabilities,  and
procedures to be followed, with respect to federal income taxes of CompX and any
subsidiaries of CompX and with respect to certain  combined  foreign,  state and
local taxes on the terms of this Agreement.

                                    Agreement

     The parties hereto agree as follows:

     Section 1. Definitions. As used in this Agreement, the following terms have
the meanings set forth below:

          (a) Code:  The  Internal  Revenue Code of 1986,  as amended,  and with
     respect to any section thereof any successor  provisions under such Code or
     any successor Code.

          (b) Combined Foreign, State and Local Taxes: For a taxable period, the
     amount of all foreign,  state and local taxes,  together  with all interest
     and penalties with respect thereto,  for which liability is computed (1) on
     the basis of a combined,  unitary or  consolidated  return  (whether at the
     initiative of the tax authority or of the taxpayer) and (2) by reference to
     one or more members of the CompX Group, one or more members of the NL Group
     and one or more  members of the  Contran  Group not  included  in the CompX
     Group.

          (c) Contran  Corporation:  A Delaware  corporation  that is the common
     parent of a group of corporations  electing to file a consolidated  federal
     income tax return and certain combined state and local returns.

          (d)  Federal  Taxes:  All  federal  income  taxes,  together  with all
     interest and penalties with respect thereto.

<PAGE>

          (e) NL Group:  NL and those of its  direct and  indirect  subsidiaries
     which join in the filing of a  consolidated  federal income tax return with
     its  common  parent,  Contran  (the  "Contran  Group"),  as such  Group  is
     constituted  from time to time.  For  purposes  of this  Agreement  (to the
     extent related to Combined  Foreign,  State and Local Taxes),  the term "NL
     Group"  shall  include  all direct  and  indirect  subsidiaries  of NL with
     reference to which Combined Foreign, State and Local Taxes are determined.

          (f) CompX Group: CompX  International Inc. and each direct or indirect
     subsidiary of CompX which would be a member of an affiliated group,  within
     the meaning of section  1504(a) of the Code,  of which CompX was the common
     parent,  as such Group is  constituted  from time to time.  For purposes of
     this Agreement (to the extent related to Combined Foreign,  State and Local
     Taxes) , the term  "CompX  Group"  shall  include  all direct and  indirect
     subsidiaries of CompX with reference to which Combined,  Foreign, State and
     Local taxes are determined.

          (g) CompX Group Tax Liability: For a taxable period, the liability for
     Federal Taxes and Combined  Foreign,  State and Local taxes, as applicable,
     that the CompX Group would have had if it were not a member of the NL Group
     or the  Contran  Group  during such  taxable  period (or during any taxable
     period prior thereto), and instead filed a separate consolidated return for
     such taxable period (and during all prior taxable  periods  beginning after
     October 1, 2004); provided,  however, that for purposes of determining such
     liability for a taxable period all tax elections  shall be consistent  with
     the tax  elections  made by Contran  for such  period.  In making  such tax
     elections it is understood  the Contran Group will make those tax elections
     that  are  beneficial  to  the  Contran  Group  on  a  consolidated  basis.
     Nevertheless,  Contran  will  use its  best  efforts  in the  case of those
     elections which affect the computation of the CompX Group Tax Liability, to
     make elections in a reasonable manner so as to minimize the CompX Group Tax
     Liability.

     Section 2. Contran as Agent.  Contran shall be the sole agent for the CompX
Group in all matters relating to the CompX Group Tax Liability.  The CompX Group
shall not (a)  terminate  such  agency or (b)  without  the  consent of Contran,
participate,  or attempt to  participate,  in any  matters  related to the CompX
Group Tax Liability, including, but not limited to, preparation or filing of, or
resolution of disputes,  protests or audits with the Internal  Revenue  Service,
state or local taxing authorities  concerning,  the Contran Group's consolidated
returns of Federal Taxes, returns of Combined Foreign,  State and Local Taxes or
the CompX Group Tax  Liability  with  respect  thereto  for any  taxable  period
beginning  after  October 1, 2004.  The CompX  Group  shall  cooperate  fully in
providing  Contran with all information and documents  necessary or desirable to
enable  Contran  to  perform  its  obligations  under  this  Section,  including
completion  of  Internal  Revenue  Service  and  state or local  tax  audits  in
connection with such CompX Group Tax Liability and  determination  of the proper
liability for such CompX Group Tax Liability.

     Section 3. Liability for Taxes; Refunds.

          (a) NL, as the common parent of the CompX Group,  shall be responsible
     for, and shall pay to Contran or a taxing  authority,  as  applicable,  the
     consolidated  tax  liability for the NL Group and has the sole right to any
     refunds received from Contran or a taxing authority, as applicable, subject
     to the provisions of Sections 5 and 6 of this Agreement.

<PAGE>

          (b) Notwithstanding  any other provision of this Agreement,  CompX and
     each  subsidiary  of CompX  which is a member of the CompX  Group  shall be
     severally liable to NL for the CompX Group Tax Liability.

          (c) CompX shall  indemnify  NL and hold it and the NL Group other than
     the CompX  Group,  harmless  from and against any  deficiency  in the CompX
     Group Tax Liability that may be due to NL.

          (d) NL shall  indemnify CompX and hold it and the CompX Group harmless
     from and against any Federal  Taxes and Combined  Foreign,  State and Local
     Taxes  attributable  to the NL Group or any  other  member  of the  Contran
     Group,  other than the CompX Group, as such taxes are determined under this
     and other tax sharing agreements.

     Section 4. Tax Returns.  NL shall file on behalf of the CompX Group any and
all  federal,  foreign,  state and local tax returns  that are  required as they
pertain to the CompX Group Tax  Liability.  The CompX  Group,  at NL's  request,
shall join in any  applicable  consolidated  returns  of  Federal  Taxes and any
returns of  Combined  State and Local  Taxes (for  which  returns  have not been
theretofore  filed) and  execute  its consent to each such filing on any form as
may be prescribed for such consent if such consent is required.  The decision of
NL's Tax Director(or any other officer so designated by NL) with  responsibility
for tax matters shall,  subject to the provisions of this Agreement,  be binding
in any dispute  between NL and the CompX Group as to what tax position should be
taken with respect to any item or transaction of the CompX Group.  The preceding
sentence  is  limited  to the tax  positions  that  affect  the CompX  Group Tax
Liability  and the  combined NL Group and Contran  Group.  In  addition,  NL and
members of the NL Group,  including CompX and members of the CompX Group,  shall
provide each other with such cooperation,  assistance and information as each of
them may  request  of the other with  respect  to the filing of any tax  return,
amended  return,  claim for refund or other document with any taxing  authority.
CompX  shall be solely  responsible  for all taxes due for the CompX  Group with
respect to tax  returns  filed by CompX or a member of the CompX  Group that are
required to be filed on a separate company basis, independent of NL.

     Section 5. Payment of CompX Group Tax  Liability for Federal  Taxes.  On or
before each date, as determined  under section 6655 of the Code,  for payment of
an installment of estimated Federal Taxes, CompX shall pay to NL an amount equal
to the  installment  which the CompX Group would have been required to pay as an
estimated  payment of Federal Taxes to the Internal  Revenue  Service if it were
filing a  separate  consolidated  return  in  respect  of the  CompX  Group  Tax
Liability.  Any balance owed with respect to the CompX Group Tax  Liability  for
such  taxable  period shall be paid to NL on or before the 15th day of the third
month after the close of such taxable period. If it is not possible to determine
the amount of such  balance on or before  such day,  (a) a  reasonable  estimate
thereof  shall be paid on or before  such day,  (b) the  amount of such  balance
shall be finally determined on or before the earlier of; (i) the 15th day of the
ninth  month after the close of such  taxable  period and (ii) the date on which
the consolidated tax return  containing the CompX Group for such period is filed
with the Internal Revenue Service,  and (c) any difference between the amount so
determined  and  the  estimated  amount  paid  shall;  (i)  in  the  case  of an
underpayment,  be promptly paid to NL and (ii) in the case of an overpayment, be
promptly refunded or applied against the estimated CompX Group Tax Liability for
the immediately following tax period, at the option of NL. If the overpayment is
not applied to the immediately  following tax period,  such overpayment shall be
promptly  refunded to the CompX Group. As between the parties to this Agreement,
the CompX Group shall be solely  responsible  for the CompX Group Tax  Liability
and  shall  have no  responsibility  for  Federal  Taxes  of the NL Group or the
Contran  Group other than payment of the CompX Group Tax Liability in accordance
with the terms of this Agreement.

<PAGE>

     Section 6. Refunds for CompX Group Losses and Credits for Federal Taxes. If
the calculation  with respect to the CompX Group Tax Liability for Federal Taxes
results in a net operating  loss ("NOL") for the current tax period that, in the
absence of a Code Section  172(b)(3)  election made by Contran,  is carried back
under Code  Sections  172 and 1502 to a prior  taxable  period or periods of the
CompX Group with respect to which the CompX Group  previously  made  payments to
NL, then,  in that event,  NL shall pay (or credit) CompX an amount equal to the
tax refund to which the CompX Group would have been entitled had the CompX Group
filed a separate  consolidated  federal income tax return for such year (but not
in excess of the net aggregate  amount of the CompX Group Tax Liability  paid to
NL with respect to the preceding two taxable  periods).  If the calculation with
respect to the CompX Group Tax  Liability  results in an NOL for the current tax
period,  that subject to the Code Section 172(b)(3) election made by Contran, is
not carried back under Code Sections 172 and 1502 to a prior  taxable  period or
periods of the CompX Group with respect to which CompX made payments to NL or is
not carried  back  because the Contran  Group does not have a  consolidated  net
operating loss for the current tax period, then, in that event such NOL shall be
an NOL  carryover  to be used in  computing  the CompX Group Tax  Liability  for
future taxable  periods,  under the law applicable to NOL carryovers in general,
as such law applies to the relevant  taxable period.  Furthermore,  if the CompX
Group would have been entitled to a refund of Federal Taxes for any year had the
CompX Group filed a separate consolidated federal income tax return for the loss
year and the carryback  year, NL shall pay to CompX the amount which CompX would
have  received as a refund from the  Internal  Revenue  Service.  Payments  made
pursuant  to this  Section  6 shall be made on the  date  that  Contran  (or any
successor  common parent of a tax group to which the NL Group is a member) files
its  consolidated  federal  income tax return for the taxable  period  involved.
Principles  similar to those discussed in this Section 6 shall apply in the case
of the utilization of all CompX Group loss and credit carrybacks and carryovers.

     Section 7.  Payment of CompX Group Tax  Liability  for  Foreign,  State and
Local Taxes. The foregoing  principles contained in Sections 5 and 6 shall apply
in similar fashion to any consolidated or combined foreign, state or other local
income tax returns,  containing any member of the NL Group and any member of the
CompX Group that is not also a member of the NL Group, which may be filed.

     Section 8.  Subsequent  Adjustments.  If any  settlement  with the Internal
Revenue Service,  foreign,  state or local tax authority or court decision which
has become final  results in any  adjustment  to any item of income,  deduction,
loss or credit to the NL Group in respect of any taxable  period subject to this
Agreement,  which,  in any such  case,  affects  or relates to any member of the
CompX Group as  constituted  during  such  taxable  period,  the CompX Tax Group
Liability  shall be  redetermined to give effect to such adjustment as if it had
been made as part of or reflected in the original  computation  of the CompX Tax
Group  Liability  and proper  adjustment  of amounts paid or owing  hereunder in
respect  of such  liability  and  allocation  shall  be  promptly  made in light
thereof.

     Section 9. Amendments. This Agreement may be amended, modified,  superseded
or  cancelled,  and any of the terms,  covenants,  or  conditions  hereof may be
waived,  only by a written instrument  specifically  referring to this Agreement
and executed by both  parties  (or, in the case of a waiver,  by or on behalf of
the party waiving compliance).  The failure of either party at any time or times
to require  performance  of any provision of this  Agreement  shall in no manner
affect the right at a later time to enforce the same.  No waiver by either party
of any  condition,  or of any breach of any term or covenant,  contained in this
Agreement, in any one or more instances, shall be deemed to be or construed as a
further or continuing waiver of any such condition or breach, or a waiver of any
other condition or of any breach of any other term or covenant.

<PAGE>

     Section 10.  Retention of Records.  NL shall  retain all tax  returns,  tax
reports,  related  workpapers  and all schedules  (along with all documents that
pertain to any such tax returns, reports or workpapers) that relate to a taxable
period in which the CompX Group is included in a  consolidated  or combined  tax
return  with NL. NL shall  make such  documents  available  to CompX at  CompX's
request. NL shall not dispose of such documents without the permission of CompX.

     Section 11. Headings. The headings of this Agreement are for convenience of
reference only, and shall not in any way affect the meaning or interpretation of
this Agreement.

     Section 12.  Governing Law. This Agreement  shall be construed and enforced
in  accordance  with the laws of the  State of  Delaware  without  regard to its
conflicts of laws provisions.

     Section  13.  Counterparts.  This  Agreement  may be  executed  in multiple
counterparts,  each of  which  shall  be an  original,  but all of  which  shall
constitute but one agreement.

     Section 14.  Successors.  This Agreement shall be binding upon and inure to
the benefit of the parties hereto and their respective  subsidiaries,  and their
respective successors and assigns.

     Section 15. Effective Date. This Agreement shall be effective as of October
1, 2004.

<PAGE>

     IN WITNESS  WHEREOF,  the parties  hereto have executed  this  Agreement on
October 5, 2004 but effective October 1, 2004.

                                        NL INDUSTRIES, INC.



                                        By:  /s/ Kelly D. Luttmer
                                             -------------------------
                                             Kelly D. Luttmer
                                             Tax Director
[Seal]

ATTEST:

/s/ A. Andrew R. Louis
-----------------------
Assistant Secretary,
NL Industries, Inc.

                                        CONTRAN CORPORATION



                                        By:  /s/ William J. Lindquist
                                             -------------------------
                                             William J. Lindquist
                                             Senior Vice President

[Seal]

ATTEST:

/s/ A. Andrew R. Louis
-----------------------
Secretary,
Contran Corporation

                                        COMPX INTERNATIONAL INC.



                                        By:  /s/ Darryl R. Halbert
                                             -------------------------
                                             Darryl R. Halbert
                                             Vice President, Chief Financial
                                             Officer and Controller

[Seal]

ATTEST:

/s/ A. Andrew R. Louis
-----------------------
Secretary,
CompX International Inc.