6-K

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 6-K

Report of Foreign Private Issuer Pursuant to Rule 13a-16 or 15d-16 of the

Securities Exchange Act of 1934

For the month of June, 2024 Commission File Number 1-14732

COMPANHIA SIDERÚRGICA NACIONAL

(Exact name of registrant as specified in its charter)

National Steel Company

(Translation of Registrant's name into English)

Av. Brigadeiro Faria Lima 3400, 20º andarSão Paulo, SP, Brazil04538-132

(Address of principal executive office)

Indicate by check mark whether the registrant files or will file annual reports under cover Form 20-F or Form 40-F.  Form 20-F ___X___ Form 40-F _______

Indicate by check mark whether the registrant by furnishing the information contained in this Form is also thereby furnishing the information to the Commission pursuant to Rule 12g3-2(b) under the Securities Exchange Act of 1934. Yes _______ No ___X____

COMPANHIA SIDERÚRGICA NACIONAL

Publicly Held Company

Corporate Taxpayer’s ID 33.042.730/0001-04

NIRE 35300396090

MATERIAL FACT

Companhia Siderúrgica Nacional ("Company") informs its shareholders and the market in general that, the majority of the 3rd Panel of the Superior Court of Justice rendered a favorable decision in the trial of the “embargos de declaração” in the “Recurso Especial” n. 1.837.538/SP held on this date, regarding the “tag along” right pursuant to article 254-A of Law n. 6,404/76, due to the sale of control of Usiminas to the Ternium Group.

The Company has not yet had access to the full decision, but will keep its shareholders and the market in general duly informed about the possible developments of this decision.

São Paulo, June 18, 2024.

Antonio Marco Campos Rabello

Executive of Finance and Investor Relations

SIGNATURE

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: June 18, 2024

FORWARD-LOOKING STATEMENTS

This press release may contain forward-looking statements. These statements are statements that are not historical facts, and are based on management's current view and estimates of future economic circumstances, industry conditions, company performance and financial results. The words "anticipates", "believes", "estimates", "expects", "plans" and similar expressions, as they relate to the company, are intended to identify forward-looking statements. Statements regarding the declaration or payment of dividends, the implementation of principal operating and financing strategies and capital expenditure plans, the direction of future operations and the factors or trends affecting financial condition, liquidity or results of operations are examples of forward-looking statements. Such statements reflect the current views of management and are subject to a number of risks and uncertainties. There is no guarantee that the expected events, trends or results will actually occur. The statements are based on many assumptions and factors, including general economic and market conditions, industry conditions, and operating factors. Any changes in such assumptions or factors could cause actual results to differ materially from current expectations.