GRIFFON CORP

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-K

For the year ended September 30, 2025

OR

Commission File No.1-06620

GRIFFON CORP ORATION

(Exact name of registrant as specified in its charter)

(212)957-5000

(Registrant’s telephone number, including area code)

Securities registered pursuant to Section 12(b) of the Act:

Securities registered pursuant to Section 12(g) of the Act:

None

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Yes x

Noo

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act. Yeso

No x

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes x Noo

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§ 232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files). Yes x Noo

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See definitions of “large accelerated filer”, “accelerated filer”, “smaller reporting company” and “emerging growth company” in Rule 12b-2 of the Exchange Act:

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Indicate by check mark whether the registrant has filed a report on and attestation to its management’s assessment of the effectiveness of its internal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issued its audit report.☒

If securities are registered pursuant to Section 12(b) of the Act, indicate by check mark whether the financial statements of the registrant included in the filing reflect the correction of an error to previously issued financial statements.☐

Indicate by check mark whether any of those error corrections are restatements that required a recovery analysis of incentive-based compensation received by any of the registrant’s executive officers during the relevant recovery period pursuant to §240.10D-1(b). ☐

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Act). Yes☐ No S

The aggregate market value of the voting and non-voting common stock held by non-affiliates of the registrant as of the close of business March 31, 2025, the registrant’s most recently completed second quarter, was approximately $3,060,000,000. The registrant’s closing price as reported by the New York Stock Exchange-Composite Transactions for March 31, 2025 was $71.50. The number of the registrant’s outstanding shares was 46,231,089 as of October 31, 2025.

DOCUMENTS INCORPORATED BY REFERENCE:

Part III — (Items 10, 11, 12, 13 and 14). Registrant’s definitive proxy statement to be filed pursuant to Regulation 14A of the Securities Exchange Act of 1934.

Griffon Corporation and Subsidiaries

TABLE OF CONTENTS

Special Notes Regarding Forward-Looking Statements

This Annual Report on Form 10-K, especially “Management’s Discussion and Analysis”, contains certain “forward-looking statements” within the meaning of the Securities Act, the Securities Exchange Act of 1934, as amended, and the Private Securities Litigation Reform Act of 1995. Such statements relate to, among other things, income (loss), earnings, cash flows, revenue, changes in operations, operating improvements, the industries in which Griffon Corporation (the “Company” or “Griffon”) operates and the United States and global economies. Statements in this Form 10-K that are not historical are hereby identified as “forward-looking statements” and may be indicated by words or phrases such as “anticipates,” “supports,” “plans,” “projects,” “expects,” “believes,” "achieves," “should,” “would,” “could,” “hope,” “forecast,” “management is of the opinion,” “may,” “will,” “estimates,” “intends,” “explores,” “opportunities,” the negative of these expressions, use of the future tense and similar words or phrases. Such forward-looking statements are subject to inherent risks and uncertainties that could cause actual results to differ materially from those expressed in any forward-looking statements. These risks and uncertainties include, among others: current economic conditions and uncertainties in the housing, credit and capital markets; Griffon’s ability to achieve expected savings and improved operational results from cost control, restructuring, integration and disposal initiatives (including the expanded CPP global outsourcing strategy announced in May 2023); the ability to identify and successfully consummate, and integrate, value-adding acquisition opportunities; increasing competition and pricing pressures in the markets served by Griffon’s operating companies; the ability of Griffon’s operating companies to expand into new geographic and product markets, and to anticipate and meet customer demands for new products and product enhancements and innovations; increases in the cost or lack of availability of raw materials such as steel, resin and wood, components or purchased finished goods, including any potential impact on costs or availability resulting from tariffs; changes in customer demand or loss of a material customer at one of Griffon’s operating companies; the potential impact of seasonal variations and uncertain weather patterns on certain of Griffon’s businesses; political events or military conflicts that could impact the worldwide economy; a downgrade in Griffon’s credit ratings; changes in international economic conditions including inflation, interest rate and currency exchange fluctuations; the reliance by certain of Griffon’s businesses on particular third party suppliers and manufacturers to meet customer demands; the relative mix of products and services offered by Griffon’s businesses, which impacts margins and operating efficiencies; short-term capacity constraints or prolonged excess capacity; unforeseen developments in contingencies, such as litigation, regulatory and environmental matters; Griffon’s ability to adequately protect and maintain the validity of patent and other intellectual property rights; the cyclical nature of the businesses of certain of Griffon’s operating companies; possible terrorist threats and actions and their impact on the global economy; effects of possible IT system failures, data breaches or cyber-attacks; the impact of pandemics on the U.S. and the global economy, including business disruptions, reductions in employment and an increase in business and operating facility failures, specifically among our customers and suppliers; Griffon’s ability to service and refinance its debt; and the impact of recent and future legislative and regulatory changes, including, without limitation, changes in tax laws. Such statements reflect the views of the Company with respect to future events and are subject to these and other risks, as previously disclosed in the Company’s Securities and Exchange Commission filings. Readers are cautioned not to place undue reliance on these forward-looking statements. These forward-looking statements speak only as of the date made. Griffon undertakes no obligation to publicly update or revise any forward-looking statements, whether as a result of new information, future events or otherwise, except as required by law.