EXHIBIT 10.5

                                   GUARANTY


      THIS GUARANTY (the  "Guaranty"),  dated as of January 31, 1997, is made by
NL  INDUSTRIES,  INC., a Delaware  corporation  (the  "Guarantor"),  in favor of
HYPOBANK  INTERNATIONAL S.A. (the "Agent"), as agent for all the Banks listed on
Schedule 1 to the Loan Agreement (as hereinafter  defined) and their  successors
and assigns (collectively,  with the Agent, the "Banks"). Capitalized terms used
herein, unless otherwise defined,  shall have the meanings set forth in the Loan
Agreement.

                             W I T N E S S E T H:

      WHEREAS,   Kronos   International,   Inc.,  a  Delaware  corporation  (the
"Borrower"),  Kronos Titan-GmbH  ("Kronos Titan"),  the Agent and the Banks are,
concurrently  herewith,  entering into that certain  Second Amended and Restated
Loan  Agreement  dated as of  January  31,  1997 (as the same may be  amended or
supplemented  from time to time,  the "Loan  Agreement"),  which Loan  Agreement
amends and restates that certain Amended and Restated Loan Agreement dated as of
October 15, 1993,  among the Borrower,  the Agent,  Banque Paribas,  as Co-Agent
(the "Co-Agent"),  and the Banks (or their predecessors in interest) (the "First
Restated  Agreement"),  which First Restated  Agreement amends and restates that
certain Loan Agreement dated as of May 30, 1990, among the Borrower,  the Agent,
the  Co-Agent  and the Banks (or their  predecessors  in interest) as amended by
that certain (i) First  Amendment  Agreement dated as of December 31, 1990, (ii)
Second Amendment  Agreement dated as of March 22, 1991 and (iii) Third Amendment
Agreement  dated as of June 15,  1992 (the  "Original  Agreement"),  pursuant to
which the Banks (or their  predecessors  in  interest)  initially  loaned to the
Borrower the principal amount of DM 1,600,000,000 (Deutsche Mark One Billion Six
Hundred  Million) (the aggregate of any and all amounts advanced by the Banks or
their  predecessors  in interest  under the Loan  Agreement,  the First Restated
Agreement and/or the Original  Agreement and outstanding at any time,  including
without limitation any and all amounts outstanding under the Term Portion or the
Revolving  Portion  (as  such  terms  are  defined  in the Loan  Agreement),  is
hereinafter called the "Loans"); and

      WHEREAS,  in order to  induce  the Banks to amend  and  restate  the First
Restated  Agreement,  the Guarantor is required to guarantee the prompt  payment
when due of all principal,  interest and other amounts that shall be at any time
payable by the Borrower or any of its  Subsidiaries  under the Loan Documents on
the terms and conditions set forth in this Guaranty;

      NOW  THEREFORE,  for and in  consideration  of the above,  and any and all
financial accommodations or extensions of credit (including, without limitation,
any loan or advance by  renewal,  refinancing  or  extension  of the  agreements
described herein) heretofore, now or hereafter made to or for the benefit of the
Borrower and/or Kronos Titan by the Banks,  the Guarantor  hereto  covenants and
agrees as follows:


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                                   ARTICLE I

                                 The Guaranty

      SECTION 1.1 The Guaranty. The Guarantor hereby unconditionally  guarantees
to the  Agent and the Banks and their  respective  successors  and  assigns  the
punctual payment, as and when due (whether by acceleration or otherwise), of

            (i)  The  principal  amount  of  the  Loans  and  all  interest  and
prepayment and other charges accruing thereunder;

            (ii) All charges,  payments,  and other  obligations of the Borrower
and/or  Kronos  Titan  accruing  under the Loan  Agreement,  the First  Restated
Agreement and/or the Original Agreement; and

            (iii) All charges,  payments and other  obligations of the Borrower,
Kronos Titan and/or any of the Subsidiaries of the Borrower  accruing under this
Guaranty or any of the other Loan Documents (all of the foregoing, collectively,
the "Secured Indebtedness").

      Upon failure by the Borrower,  Kronos Titan and/or any of the Subsidiaries
of the Borrower to pay punctually any such amount,  the Guarantor agrees that it
will  forthwith  on demand  pay the  amount  not so paid at the place and in the
manner specified in the Loan Documents or as otherwise notified to the Guarantor
by the Agent.

      SECTION  1.2  Guarantor's  Obligation.   The  Guarantor  agrees  that  its
liability  hereunder  shall be as a sole and  primary  obligor and not merely as
surety and that its  liability is absolute and  unconditional,  and shall not be
subject to any right of set-off or  counterclaim  and shall remain in full force
and effect until the entire Secured Indebtedness shall have been paid in full.

      SECTION 1.3 Waiver.  The Guarantor  hereby  waives,  to the fullest extent
permitted  by law,  notice of the  acceptance  hereof,  diligence,  presentment,
demand of payment or  otherwise,  and any right to  require a  proceeding  first
against the Borrower,  Kronos Titan and/or any other Person  (including  without
limitation any other Guarantor).

      SECTION 1.4 No Effect or Impairment.  The Guarantor hereby consents to and
agrees  that its  obligations  under this  Guaranty  will not be  discharged  or
affected by: (i) any acceptance, forbearance or release in respect of the rights
of the Agent or the Banks or any  subsequent  holder under the Loan Agreement or
the Loan Documents,  including,  without  limitation,  any release of any of the
Collateral or any other guaranty of the Loans; (ii) any waiver or release of any
right or option of the Agent or the  Banks or any  subsequent  holder  under the
terms  of the  Loan  Agreement  or  other  Loan  Documents,  including,  without
limitation,  any release of any of the  Collateral or any other  guaranty of the
Loans; (iii) any modification,  extension,  renewal or amendment of the terms of
the  Loan  Agreement  or other  Loan  Documents;  (iv)  the  fact  that the Loan
Agreement   or  any  other  Loan   Documents   shall  be  invalid,   illegal  or
unenforceable,  in  whole  or in  part,  for any  reason;  (v) the  receipt  and
acceptance of notes, checks or other instruments for

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the payment of money by the  Borrower,  Kronos Titan and/or any  Subsidiary  and
extensions and renewals  thereof;  or (vi) except as otherwise  provided herein,
any  other  act or  omission  of any  kind  by the  Agent  or the  Banks  or any
subsequent  holder or the  Borrower  or Kronos  Titan or any other  circumstance
whatsoever  which  might  constitute  a  legal  or  equitable  discharge  of the
Guarantor, including, without limitation, the bankruptcy of the Borrower, Kronos
Titan and/or any Subsidiary.

      SECTION 1.5  Payments.  All payments  provided for herein shall be made in
immediately  available funds in Deutsche Mark ("DM");  provided,  however,  that
payments  provided for herein shall be made in  immediately  available  funds in
U.S.  Dollars if and to the extent that the payment  provided for herein relates
to an amount payable by the Borrower  and/or Kronos Titan in U.S.  Dollars.  The
obligation  of the  Guarantor to make payment in DM of any amounts due hereunder
to the Agent shall not be discharged or satisfied by any tender, or any recovery
pursuant to any judgment,  which is expressed in or converted  into any currency
other than DM, except to the extent that such tender or recovery shall result in
the actual receipt by the Agent of the full amount of DM expressed to be due and
owing in respect of the  principal  amount of and interest  accrued on the Loans
and in regard to the other parts of the Secured  Indebtedness  expressed  in DM.
The Guarantor  agrees that the  obligations  to make payments in DM as aforesaid
shall be enforceable  as an  alternative  or additional  cause of action for the
purpose of recovery  in DM of the amount (if any) by which such  actual  receipt
shall fall short of the full amount of DM  expressed to be payable in respect of
any  amount due  hereunder,  and shall not be  affected  by any  judgment  being
obtained for other sums in any other currency in enforcement of this Guaranty.

      SECTION  1.6 Net  Payments.  All  payments  by the  Guarantor  under  this
Agreement  shall be made without setoff or  counterclaim  and free and clear of,
and without withholding or deduction for or on account of, any present or future
taxes (other than Excluded  Taxes) now or hereafter  imposed on the recipient of
such payment or its income, property, assets or franchises, except to the extent
that such withholding or deduction is required by applicable law or is permitted
under the Loan Agreement.

      If any such  withholding  or deduction is required by applicable law or is
permitted under the Loan Agreement, the Guarantor will:

            (i) pay to the relevant tax  authorities the full amount so required
to be withheld or deducted  when and as the same shall become due and payable to
such tax authorities;

            (ii) promptly forward to the Agent and each of the affected Banks an
official  receipt or other  documentation  satisfactory to the Agent  evidencing
such payment to such tax authorities; and

            (iii) except to the extent that such withholding or deduction is for
Excluded Taxes or, under the terms of the Loan Agreement, for additional amounts
which are not payable or have been  waived,  pay to the Agent for the account of
the relevant recipient such additional amount as is necessary to ensure that the
net amount actually received by each recipient will equal

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the full amount such  recipient  would have received had no such  withholding or
deduction been required.

      SECTION 1.7  Subrogation.  The Guarantor  shall not have any right to, and
will not,  exercise any rights that it may acquire by way of  subrogation  under
this Guaranty (by any payment made hereunder or otherwise) until all the Secured
Indebtedness  shall have been paid in full.  If any amount  shall be paid to the
Guarantor on account of such subrogation rights at any time when all the Secured
Indebtedness  shall  not have been paid in full,  such  amount  shall be held in
trust for the benefit of the Agent and the Banks and shall  forthwith be paid to
the Agent to be credited and applied to the payment of the Secured Indebtedness,
whether  matured  or  unmatured,  in  accordance  with  the  terms  of the  Loan
Agreement.  If (i) all the Secured Indebtedness shall be paid in full, the Agent
and the Banks  will,  at the  Guarantor's  request,  execute  and deliver to the
Guarantor appropriate documents,  without recourse and without representation or
warranty,  necessary to evidence the transfer by subrogation to the Guarantor of
an interest  in the  Secured  Indebtedness  resulting  from such  payment by the
Guarantor.

      SECTION  1.8  Revival of  Obligation.  If,  after the Agent's or the other
Banks'  receipt  of any  payment  from  the  Borrower  of all or any part of the
amounts  paid  under this  Guaranty,  or after the  Agent's or the other  Banks'
collection of the proceeds  from the sale of any  Collateral or from the payment
under any other guaranty,  the Agent or the Banks are petitioned or compelled to
return any such  payment or  proceeds,  because  such  payment  or  proceeds  is
invalidated,  declared fraudulent,  set aside, determined to be void or voidable
as a preference, an impermissible setoff, or for any reason whatsoever, then the
Borrower's obligations (and Kronos Titan's obligations,  if applicable) shall be
deemed to be revived and this Guaranty  shall  continue in full force as if such
payment  or  proceeds  had not been  received  by the Agent or the  Banks  until
payment in full is made by the Guarantor.  In addition,  the Guarantor agrees to
indemnify and hold the Agent and the Banks harmless from and against and for any
and all  damages,  losses,  costs or  expenses  (including  without  limitation,
reasonable  attorneys'  fees) incurred by them in connection with such surrender
or return.

                                  ARTICLE II

                           Jurisdiction and Service

      SECTION 2.1 Consent to Jurisdiction,  Venue. The Guarantor  represents and
warrants  that it is not  entitled to immunity  from  judicial  proceedings  and
agrees  that,  should  the Agent  bring any suit,  action or  proceeding  in the
jurisdiction  described  below to enforce any  obligation  or  liability  of the
Guarantor under this Guaranty,  no immunity from such suit, action or proceeding
will be claimed by or on behalf of the  Guarantor  or with respect to its assets
or  property.  The  Guarantor  irrevocably  submits to the  jurisdiction  of any
federal or state court sitting in the City of New York, State of New York, or in
the City of Dallas,  State of Texas, over any suit, action or proceeding arising
out of or relating to this Guaranty.  The Guarantor  irrevocably  waives, to the
fullest  extent  permitted by law, any  objection  which it has or may hereafter
have to the laying of the venue of any such suit,  action or proceeding  brought
in such court and any claim that any such suit, action or proceeding  brought in
such court has been

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brought  in  an  inconvenient   forum.  The  Guarantor  agrees  that  final  and
non-appealable judgment in any such suit, action or proceeding brought in such a
court shall be conclusive  and binding upon the Guarantor and may be enforced in
any other courts to the jurisdiction of which the Guarantor is subject by a suit
upon such  judgment,  provided  that  service of process  is  effected  upon the
Guarantor  in one of the manners  specified in Section 2.3 below or as otherwise
permitted by law.

      SECTION  2.2  Appointment  of  Agent.  The  Guarantor  hereby  irrevocably
designates  and  appoints  The  Prentice-Hall   Corporation  System,  Inc.,  c/o
Corporation Service Company, 500 Central Avenue,  Albany, New York 12206, as its
authorized  agent to accept and acknowledge on its behalf service of any and all
process  which may be served in any suit,  action or  proceeding  of the  nature
referred to in Section 2.1 in any court  sitting in The City of New York,  State
of New York. Said  designation and  appointment  shall be irrevocable  until the
Secured  Indebtedness  shall have been paid in full.  If such agent for  service
shall  cease  so to act,  the  Guarantor  covenants  and  agrees  that it  shall
irrevocably  designate and appoint without delay another such agent satisfactory
to the Agent and shall deliver promptly to the Agent evidence in writing of such
other agent's acceptance of such appointment.

      SECTION 2.3 Service of Process.  The Guarantor  hereby consents to process
being  served in any suit,  action or  proceeding  of the nature  referred to in
Section  2.1 either  (a) by the  mailing of a copy  thereof by  registered  mail
(registered  airmail  if  addressed  to a location  in a country  other than the
country of mailing),  postage prepaid,  return receipt requested, to the address
for the Guarantor set forth on the signature page hereof or to any other address
of which the Guarantor  shall have given written  notice to Agent or such holder
or (b) by serving a copy  thereof  upon The  Prentice-Hall  Corporation  System,
Inc., c/o Corporation  Service  Company,  500 Central Avenue,  Albany,  New York
12206,  as the Guarantor's  agent for service of process  (provided that, to the
extent  lawful and possible,  written  notice of said service upon said agent of
the  Guarantor  shall be  mailed  by  registered  mail  (registered  airmail  if
addressed to a location in a country other than the country of mailing), postage
prepaid,  return receipt  requested,  to the Guarantor at its address  specified
above or to any other  address of which the  Guarantor  shall have given written
notice to the Agent.  The Guarantor  irrevocably  waives,  to the fullest extent
permitted by law, all claim of error by reason of any such service (but does not
waive any right to assert lack of subject matter  jurisdiction)  and agrees that
such service (i) shall be deemed in every respect  effective  service of process
upon the Guarantor in any such suit, action or proceeding and (ii) shall, to the
fullest extent  permitted by law, be taken and held to be valid personal service
upon and personal delivery to the Guarantor.

      SECTION 2.4 No Limitation on Service or Suit. Nothing in Sections 2.1, 2.2
or 2.3 above shall affect the right of the Agent to serve  process in any manner
permitted  by law or limit  the  right of the  Agent  or other  holder  to bring
proceedings against the Guarantor in the courts of any other jurisdiction.


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                                  ARTICLE III

                              General Conditions

      SECTION 3.1  Survival.  All  covenants,  agreements,  representations  and
warranties  made by the  Guarantor in this Guaranty and in any  certificates  or
other  documents  delivered  pursuant hereto shall survive and shall continue in
full force and effect until the Secured Indebtedness is paid in full.

      SECTION  3.2  Assignment.  The Agent may  assign any and all rights it has
hereunder,  either in whole or in part;  the Guarantor may not assign any of its
rights or indebtedness, liabilities or obligations under this Guaranty except as
may be permitted in the Loan Agreement.

      SECTION 3.3  Communications  and Notices.  All  communications and notices
provided for in this Guaranty shall be in English, shall be in writing and shall
be in accord with Article 26 of the Loan Agreement.

      SECTION 3.4 Stay of Acceleration.  If acceleration of the time for payment
of  any  amount  payable  by  the  Borrower,  Kronos  Titan  and/or  any  of the
Subsidiaries  of the  Borrower  under  the Loan  Documents  is  stayed  upon the
insolvency,  bankruptcy or reorganization  of the Borrower,  Kronos Titan and/or
any such Subsidiary,  all such amounts otherwise  subject to acceleration  under
the terms of the Loan  Documents  shall  nonetheless be payable by the Guarantor
hereunder forthwith on demand by the Agent.

      SECTION 3.5  Limitation  on  Guarantor's  Obligations.  The  indebtedness,
liabilities  and  obligations of the Guarantor  hereunder shall be limited to an
aggregate  amount  equal  to the  largest  amount  that  would  not  render  its
indebtedness,  liabilities and obligations  hereunder subject to avoidance under
Section 548 of the Bankruptcy  Code or any  applicable  provisions of comparable
state law.

      SECTION 3.6 Governing  Law. This Guaranty shall be construed in accordance
with, and governed by the laws of, the State of New York.

      SECTION  3.7  Headings  of  Articles  and  Sections.  The  headings of the
Articles and Sections of this  Guaranty  are inserted for  convenience  only and
shall not be deemed to constitute a part of this Guaranty.

      SECTION 3.8 Severability.  In case one or more of the provisions contained
in this Guaranty shall be invalid,  illegal or unenforceable in any respect, the
validity,  legality and  enforceability  of the remaining  provisions  contained
herein shall not in any way be affected or impaired thereby.

      SECTION 3.9  Execution in  Counterparts.  This Guaranty may be executed in
one or more counterparts,  each of which when executed and delivered shall be an
original and all of which shall together constitute one and the same instrument.

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      SECTION 3.10 Entire Agreement. This Guaranty embodies the entire agreement
and  understanding  between the Agent and the Guarantor  relating to the subject
matter hereof and supersedes all prior agreements and understandings relating to
the subject matter hereof.

      SECTION 3.11 No Waivers.  No waiver by any party of any conditions,  or of
any breach of any term,  covenant,  representation or warranty  contained in the
instruments  evidencing the Loans, the Loan Agreement,  this Guaranty, or any of
the other Loan Documents 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
waiver of any other  condition  or of any  breach of any other  term,  covenant,
representation  or warranty  thereof;  nor shall any single or partial  exercise
thereof  preclude any other or further  exercise  thereof or the exercise of any
other right, power or privilege.

      SECTION 3.12 Changes, Waivers, Amendments and Modifications.  Neither this
Guaranty nor any provision hereof may be modified or amended orally, but only by
a statement in writing  entered into by the  Guarantor  and the Agent,  provided
however,  that no such agreement shall (i) affect the indebtedness,  liabilities
and  obligations  of the  Guarantor  under  Article I hereof or (ii)  modify the
provisions of this Section 3.12,  without the consent of the Banks in accordance
with the Loan Agreement.

      SECTION 3.13 Definitions. Terms used but not defined herein shall have the
meanings provided for in the Loan Agreement unless otherwise  expressly provided
or unless the context hereof otherwise requires.

      SECTION 3.14 Costs and  Expenses.  The  Guarantor  covenants and agrees to
reimburse  the  Agent  for all  reasonable  out-of-pocket  costs  and  expenses,
including  without  limitation  reasonable  attorneys'  fees  and  court  costs,
incurred by the Agent in enforcing this Guaranty, and the Guarantor acknowledges
and agrees that all such sums to be so reimbursed by it to the Agent are part of
the Secured Indebtedness.

      SECTION 3.15 Limitation of Special Damages.  The Guarantor hereby releases
each of the Agent and all of the Banks from any liability  for, and waives,  and
agrees not to claim or sue for any special,  indirect or consequential  damages,
suffered by the undersigned,  in connection with any claim (whether  sounding in
tort, contract or otherwise) in any way arising out of, related to, or connected
with  the  Loan  Documents,  whether  such  claim is  asserted  before  or after
repayment in full of all of the Borrower's  and/or Kronos Titan's  indebtedness,
liabilities and obligations. This waiver shall inure to the benefit of the Agent
and the Banks and their  respective  successors and assigns and shall be binding
on the Guarantor and its successors and assigns.

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      IN WITNESS  WHEREOF,  the parties  hereto have caused this  Guaranty to be
duly executed as of the date first stated above.

                               NL INDUSTRIES, INC.

                                    By:       /s/ Susan E. Alderton
                                    Name:     Susan E. Alderton
                                    Title:    Vice President & Treasurr
                                    Address:  16825 Northchase Drive, Suite 1200
                                              Houston, Texas  77060

                                    HYPOBANK INTERNATIONAL S.A.

                                    By:       /s/ Michael Bisch
                                    Name:     Michael Bisch
                                    Title:    Charge de Service
                                    Address:  4, rue Alphonse Weicker
                                              L-2721 Luxembourg-Kirchberg

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