☒QUARTERLY REPORT PURSUANT TO SECTION13 OR 15(d)OFTHE SECURITIES EXCHANGE ACT OF 1934For the quarterly period ended March 31, 2026OR NL INDUSTRIES,INC. (Exact name of Registrant as specified in its charter) New Jersey13-5267260(State or other jurisdiction ofincorporation or organization)(IRS EmployerIdentification No.)5430 LBJ Freeway, Suite1700Dallas, Texas 75240-2620(Address of principal executive offices)Registrant’s telephone number, including area code: (972)233-1700 Securities registered pursuant to Section12(b)of the Act: Indicate by check mark whether the registrant (1)has filed all reports required to be filed by Section13 or15(d)of the Securities Exchange Act of 1934 during the preceding 12months and (2)has been subject to suchfiling requirements for the past 90days.Yes☒No☐ Indicate by check mark whether the registrant has submitted electronically every Interactive Data File requiredto be submitted pursuant to Rule405 of Regulation S-T during the preceding 12months (or for such shorterperiod that the registrant was required to submit such files).Yes☒No☐ Indicate by check mark whether the Registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, smaller reporting company or an emerging growth company. See the definitions of “largeaccelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” inRule12b-2 of the Exchange Act. Large accelerated filerNon-accelerated filerEmerging growth company Accelerated filer☐Smaller reporting company If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transitionperiod for complying with any new or revised financial accounting standards provided pursuant to Section13(a)of theExchange Act.☐ Indicate by check mark whether the registrant is a shell company (as defined in Rule12b-2 of the Act).Yes☐No☒Number of shares of the registrant’s common stock, $.125 par value per share, outstanding on May 1, 202648,862,734. NL INDUSTRIES,INC. AND SUBSIDIARIES INDEX Part I.FINANCIAL INFORMATION Item 1.Financial Statements Condensed Consolidated Balance Sheets -December 31, 2025; March 31, 2026 (unaudited)3Condensed Consolidated Statements of Income (unaudited) -Three months ended March 31, 2025 and 20265Condensed Consolidated Statements of Comprehensive Income (unaudited) -Three months ended March 31, 2025 and 20266Condensed Consolidated Statements of Equity (unaudited) -Three months ended March 31, 2025 and 20267Condensed Consolidated Statements of Cash Flows (unaudited) -Three months ended March 31, 2025 and 20268Notes to Condensed Consolidated Financial Statements (unaudited)9Item 2.Management’s Discussion and Analysis of Financial Condition and Results of Operations18Item 3.Quantitative and Qualitative Disclosure About Market Risk31Item 4.Controls and Procedures32Part II.OTHER INFORMATION32Item 1.Legal Proceedings32Item 1A.Risk Factors33Item 6.Exhibits34 Items 2, 3, 4 and 5 of PartII are omitted because there is no information to report. NL INDUSTRIES,INC. AND SUBSIDIARIES (In thousands) NL INDUSTRIES,INC. AND SUBSIDIARIES (In thousands) NL INDUSTRIES,INC. AND SUBSIDIARIES CONDENSED CONSOLIDATED STATEMENTS OF INCOME (In thousands, except per share data) NL INDUSTRIES,INC. AND SUBSIDIARIESCONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME(In thousands) Three months endedMarch31,20252026(unaudited)Net income$1,322$5,094Other comprehensive income (loss), net of tax:Currency translation4,1851,015Defined benefit pension plans31786Other postretirement benefit plans(33)1Total other comprehensive income, net4,4691,102Comprehensive income5,7916,196Comprehensive income attributable to noncontrolling interest655750Comprehensive income attributable to NL stockholders$5,136$5,446 (In thousands) NL INDUSTRIES,INC. AND SUBSIDIARIESCONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS(In thousands) NL INDUSTRIES,INC. AND SUBSIDIARIES NOTESTO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS March 31, 2026 (unaudited) Note1– Organization and basis of presentation: Organization– At March 31, 2026, Valhi,Inc. (NYSE: VHI) held approximately 83% of our outstandingcommon stock and a wholly-owned subsidiary of Contran Corporation held approximately 91% of Valhi’s outstandingcommon stock. A majority of Contran’soutstanding voting stock is held directly by Lisa K. Simmons and by familystockholders (Thomas C. Connelly (the husband of Ms. Simmons’ late sister), a family-owned entity and variousfamily trusts established for the benefit of Ms.Simmons, Mr. Connelly and their children) who are required to votetheir shares of Contran voting stock in the same manner as Ms. Simmons. Such voting rights are personal toMs.Simmons and last through April22, 2030. The remainder of Contran’s outstanding voting stock is held by anothertrust (the “Family Trust”), which was established for the benefit of Ms.Simmons and her late sister and their childrenand for which a th