EXHIBIT 21.1

                                          SUBSIDIARIES OF THE REGISTRANT



                                                                                                  % of Voting
                                                                 Jurisdiction Of               Securities Held at
                                                                  Incorporation                    December
                       Name of Corporation                      or  Organization                 31,  2005 (1)
                       -------------------                     ------------------                -------------

                                                                                               
Amcorp, Inc.                                                       Delaware                          100%
       ASC Holdings, Inc.                                          Utah                              100%
       Amalgamated Research, Inc.                                  Idaho                             100%

Andrews County Holdings, Inc.                                      Delaware                          100%
       Waste Control Specialists LLC                               Delaware                          100%
         Tecsafe LLC                                               Delaware                          100%

Kronos Worldwide, Inc. (2)                                         Delaware                           57%

NL Industries, Inc. (2), (3), (5)                                  New Jersey                         83%
    CompX Group, Inc. (4)                                          Delaware                           82%
      CompX International Inc. (5)                                 Delaware                           83%

Tremont LLC                                                        Delaware                          100%
       TRECO L.L.C.                                                Nevada                            100%
         Basic Management, Inc.                                    Nevada                             32%
           The Landwell Company LP                                 Delaware                           50%
         The Landwell Company LP                                   Delaware                           12%
       TRE Holding Corporation                                     Delaware                          100%
         TRE Management Company                                    Delaware                          100%
       Tremont Colorado Corporation                                Delaware                          100%
       Tall Pines Insurance Company                                Vermont                           100%
       Titanium Metals Corporation (2) - (6)                       Delaware                           37%

Valcor, Inc.                                                       Delaware                          100%
       Medite Corporation                                          Delaware                          100%

Impex Realty Holding, Inc.                                         Delaware                          100%


(1) Held by the Registrant or the indicated subsidiary of the Registrant.

(2)  Subsidiaries  of Kronos are  incorporated  by  reference to Exhibit 21.1 of
Kronos'  Annual  Report on Form 10-K for the year ended  December 31, 2005 (File
No.  333-100047).  NL owns an additional 36% of Kronos directly and a subsidiary
of TIMET owns an additional .1% of Kronos directly.

(3)  Subsidiaries  of NL are  incorporated  by reference to Exhibit 21.1 of NL's
Annual  Report on Form  10-K for the year  ended  December  31,  2005  (File No.
1-640). A subsidiary of TIMET owns an additional .5% of NL directly.

(4) Titanium Metals Corporation ("TIMET") owns the other 18% of CompX Group.

(5)  Subsidiaries  of CompX are  incorporated  by  reference  to Exhibit 21.1 of
CompX's  Annual  Report on Form 10-K for the year ended  December 31, 2005 (File
No.  1-13905).  NL and a  subsidiary  of  TIMET  own an  additional  2% and  3%,
respectively, of CompX International directly.

(6)  Subsidiaries  of TIMET are  incorporated  by  reference  to Exhibit 21.1 of
TIMET's  Annual  Report on Form 10-K for the year ended  December 31, 2005 (File
No. 0-28538). The Registrant owns an additional 4% of TIMET directly.