6-K
GERDAU S.A. (GGB)
U.S. SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
FORM 6-K
REPORT OF FOREIGN PRIVATE ISSUER
PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE
SECURITIESEXCHANGE ACT OF 1934
Dated December 2, 2025
Commission File Number 1-14878
GERDAU S.A.
(Translation of Registrant’s Name into English)
Av. Dra. Ruth Cardoso, 8,501 – 8° andar
São Paulo, São Paulo - Brazil CEP 05425-070
(Address of principal executive offices)
Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F.
Form 20-F x Form 40-F ¨
Exhibit Index
| Exhibit | Description of Exhibit |
|---|---|
| 99.1 | Notice to the Market, December 2, 2025 |
SIGNATURES
Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this Report to be signed on its behalf by the undersigned, thereunto duly authorized.
Date: December 2, 2025
| GERDAU<br> S.A. | |
|---|---|
| By: | /s/<br> Rafael Dorneles Japur |
| Name: | Rafael<br> Dorneles Japur |
| Title: | Vice<br> President and Investor Relations Director |
Exhibit 99.1
GERDAU S.A.
Corporate Tax ID (CNPJ/MF): 33.611.500/0001-19
Company Registry (NIRE): 35300520696
NOTICE TO THE MARKET
GERDAU S.A. (B3: GGBR / NYSE: GGB) (“Company”), complementing the notice to the market dated October 30, 2025, informs that its subsidiary GUSAP III LP concluded, on December 02, 2025, the financial settlement of the prepayment of all Bonds issued, with a principal amount of US$ 500,000,000.00, interest rate of 4.25% and maturity in 2030.
The total amount of the redemption corresponded to US$ 509,710,576.46, plus interest accrued to date, in accordance with the conditions established in the Indenture for execution of financial settlement.
São Paulo, December 02, 2025
Rafael Dorneles Japur
Vice-President and
Investor Relations Officer