Companhia Siderúrgica Nacional : Fato Relevante - Initial Public Offering of shares issued by CSN CIMENTOS S.A.

COMPANHIA SIDERÚRGICA NACIONAL

Publicly Held Company

Corporate Taxpayer ID (CNPJ/ME): 33.042.730/0001-04

NIRE 35-3.0039609.0

MATERIAL FACT

Companhia Siderúrgica Nacional ("CSN" or "Company") informs its shareholders and the market in general that, in a meeting held on April 28, 2021, the Company's Board of Directors authorized its directors to take the necessary measures to carry out an initial public offering of shares issued by CSN CIMENTOS S.A., as well as the hiring of legal and financial advisors and preparation of related studies. The Company will keep its shareholders and the market informed of any relevant updates in relation to this matter through its usual channels for the disclosure of periodic and occasional information, namely, the CVM website (www.cvm.gov.br), B3 (www.b3.com.br) and the Company (http://ri.csn.com.br/). This material fact is exclusively informative in terms of the legislation and regulations in force, and must not, under any circumstances, be considered and / or interpreted as, nor constituting, an investment recommendation or an offer to sell, or a solicitation or an offer to buy any securities in Brazil, the United States of America or any other jurisdiction.

São Paulo, April 28, 2021.

Marcelo Cunha Ribeiro

Executive Director and Investor Relations Officer