COMPX INTERNATIONAL INC

NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS

March 31, 2026

(unaudited)

Note 1 – Organization and basis of presentation:

Organization. We (NYSE American: CIX) were approximately 87% owned by NL Industries, Inc. (NYSE: NL) at March 31, 2026. At March 31, 2026, Valhi, Inc. (NYSE: VHI) owned approximately 83% of NL’s outstanding common stock and a wholly-owned subsidiary of Contran Corporation owned approximately 91% of Valhi’s outstanding common stock. A majority of Contran’s outstanding voting stock is held directly by Lisa K. Simmons, and by family stockholders (Thomas C. Connelly (the husband of Ms. Simmons’ late sister), a family-owned entity and various family trusts established for the benefit of Ms. Simmons, Mr. Connelly and their children) who are required to vote their shares of Contran voting stock in the same manner as Ms. Simmons. Such voting rights are personal to Ms. Simmons and last through April 22, 2030. The remainder of Contran’s outstanding voting stock is held by another trust (the “Family Trust”), which was established for the benefit of Ms. Simmons and her late sister and their children and for which a third-party financial institution serves as trustee. Consequently, at March 31, 2026, Ms. Simmons and the Family Trust may be deemed to control Contran, and therefore may be deemed to indirectly control the wholly-owned subsidiary of Contran, Valhi, NL and us.

Basis of presentation. Consolidated in this Quarterly Report are the results of CompX International Inc. and its subsidiaries. The unaudited Condensed Consolidated Financial Statements contained in this Quarterly Report have been prepared on the same basis as the audited Consolidated Financial Statements included in our Annual Report on Form 10-K for the year ended December 31, 2025 that we filed with the Securities and Exchange Commission (“SEC”) on March 4, 2026 (the “2025 Annual Report”). In our opinion, we have made all necessary adjustments (which include only normal recurring adjustments) in order to state fairly, in all material respects, our consolidated financial position, results of operations and cash flows as of the dates and for the periods presented. We have condensed the Consolidated Balance Sheet at December 31, 2025 contained in this Quarterly Report as compared to our audited Consolidated Financial Statements at that date, and we have omitted certain information and footnote disclosures (including those related to the Consolidated Balance Sheet at December 31, 2025) normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”). Our results of operations for the interim period ended March 31, 2026 may not be indicative of our operating results for the full year. The Condensed Consolidated Financial Statements contained in this Quarterly Report should be read in conjunction with our 2025 Consolidated Financial Statements contained in our 2025 Annual Report.

Our operations are reported on a 52 or 53-week year. For presentation purposes, annual and quarterly information in the Condensed Consolidated Financial Statements and accompanying notes are presented as ended March 31, 2025, December 31, 2025 and March 31, 2026. The actual dates of our annual and quarterly periods are March 30, 2025, December 28, 2025 and March 29, 2026, respectively. Unless otherwise indicated, references in this report to “we”, “us” or “our” refer to CompX International Inc. and its subsidiaries, taken as a whole.

• 7 -

Note 2 – Business segment information:

Our chief operating decision maker (“CODM”) evaluates segment performance based on segment operating income, which is defined as income before income taxes, exclusive of certain general corporate income and expense items (primarily interest income) and certain non-recurring items (such as gains or losses on the disposition of long-lived assets outside the ordinary course of business).

Intersegment sales are not material.

n

• 8 -

Note 3 – Accounts receivable, net:

Note 4 – Inventories, net:

Note 5 – Accounts payable and accrued liabilities:

• 9 -

Note 6 – Income taxes:

The provision for income taxes and the difference between such provision for income taxes and the amount that would be expected using the U.S. federal statutory income tax rate of 21% are presented below.

On July 4, 2025, the One Big Beautiful Bill Act was signed into law. It did not have a material impact on our consolidated financial statements.

Note 7 – Leases:

In March 2026, we entered into an operating lease for our distribution center located in Southern California. Upon commencement, we recognized an operating lease right-of-use asset and a corresponding operating lease liability, which are included in our Condensed Consolidated Balance Sheet. As of March 31, 2026, the remaining lease term of our operating lease was approximately 7 years and the discount rate associated with such lease was 6.75%.

Note 8 – Commitments and contingencies:

From time to time, we may be involved in various environmental, contractual, product liability, patent (or intellectual property), employment and other claims and disputes incidental to our business. At least quarterly our management discusses and evaluates the status of any pending litigation to which we are a party. The factors considered in such evaluation include, among other things, the nature of such pending cases, the status of such pending cases, the advice of legal counsel and our experience in similar cases (if any). Based on such evaluation, we make a determination as to whether we believe (i) it is probable a loss has been incurred, and if so if the amount of such loss (or a range of loss) is reasonably estimable, or (ii) it is reasonably possible but not probable a loss has been incurred, and if so if the amount of such loss (or a range of loss) is reasonably estimable, or (iii) the probability a loss has been incurred is remote. We have not accrued any amounts for litigation matters because of the uncertainty of the liability and inability to reasonably estimate the liability, if any. We currently believe the disposition of all claims and disputes, individually or in the aggregate, should not have a material adverse effect on our Consolidated Financial Statements, results of operations or liquidity.

Note 9 – Financial instruments:

The following table presents the financial instruments that are not carried at fair value but which require fair value disclosure:

Due to their near-term maturities, the carrying amounts of accounts receivable and accounts payable are considered equivalent to fair value. See Notes 3 and 5.

Note 10 – Related party transactions:

From time to time, we may have loans and advances outstanding between us and various related parties pursuant to term and demand notes. We generally enter into these loans and advances for cash management purposes. When we loan funds to related parties, we are generally able to earn a higher rate of return on the loan than we would earn if we invested the funds in other instruments, and when we borrow from related parties, we are generally able to pay a lower rate of interest than we would pay if we had incurred third-party indebtedness. While certain of these loans to affiliates

• 10 -

may be of a lesser credit quality than cash equivalent instruments otherwise available to us, we believe we have considered the credit risks in the terms of the applicable loans. In this regard, we have an unsecured revolving demand promissory note with Valhi under which, as amended, we agreed to loan Valhi up to $25 million. Our loan to Valhi, as amended, bears interest at prime plus 1.00%, payable quarterly, with all principal due on demand, but in any event no earlier than December 31, 2027. Loans made to Valhi at any time under the agreement are at our discretion. At March 31, 2026, the outstanding principal balance receivable from Valhi under the promissory note was $7.4 million. Interest income (including unused commitment fees) on our loan to Valhi was $.2 million for each of the three months ended March 31, 2025 and 2026.

Note 11 – Recent accounting pronouncements:

In November 2024, the FASB issued ASU No. 2024-03,Reporting Comprehensive Income - Expense Disaggregation Disclosures. The ASU requires additional information about specific expense categories in the notes to financial statements for both interim and annual reporting periods. The ASU is effective for us beginning with our 2027 Annual Report, and for interim reporting in the first quarter of 2028, with early adoption permitted. We are in the process of evaluating the additional disclosure requirements.