VALE Vale SA

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United States

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

August 2017

Vale S.A.

Avenida das Américas, No. 700 — Bloco 8, Sala 218
22640-100 Rio de Janeiro, RJ, Brazil

(Address of principal executive office)

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

(Check One) Form 20-F x Form 40-F o

(Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(1))

(Check One) Yes o No x

(Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(7))

(Check One) Yes o No x

(Indicate by check mark whether the registrant by furnishing the information contained in this Form is also thereby furnishing information to the Commission pursuant to Rule 12g3-2(b) under the Securities Exchange Act of 1934.)

(Check One) Yes o No x

(If “Yes” is marked, indicate below the file number assigned to the registrant in connection with Rule 12g3-2(b). 82-    .)

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LISTED COMPANY

CORPORATE TAX CODE (CNPJ) No. 33.592.510/0001-54

BOARD OF TRADE REGISTRATION (NIRE) Nº. 33.300.019.766

EXCERPT OF THE MINUTES OF THE

ORDINARY BOARD OF DIRECTORS MEETING

On August 24 th , 2017, at 9:30 am, met at Rua Almirante Guilhem, 378, 7º floor, Rio de Janeiro, RJ, the effective members, Messrs. Gueitiro Matsuo Genso — Chairman, Fernando Jorge Buso Gomes — Vice-Chairman, Dan Conrado, Marcel Juviniano Barros, Eduardo Refinetti Guardia, Denise Pauli Pavarina, Eduardo de Salles Bartolomeo, Oscar Augusto de Camargo Filho, Lucio Azevedo, and the alternate, Mr. Yoshitomo Nishimitsu, and also Mr. Clovis Torres, Executive Officer and General Counsel of Vale S.A. (“Vale”), as secretary, having unanimously resolved upon the following: “ CONVERSION OF VALE PREFERRED SHARES — (...) the Board of Directors approved, with a favorable report of the Financial Committee, submit to the Extraordinary Shareholders Meeting of Vale and Special Preferred Shareholders Meeting, the proposal to convert the total of the remaining 307,140,096 preferred shares into common shares (Conversion of the Remaining Shares), in the ratio of 0.9342 common share for each class A preferred share of Vale, (…).” I hereby attest that the item above was excerpted from the Minutes taken from the Registry of the Minutes of the Board of Directors Meetings of the Company.

Rio de Janeiro, 24 th  August, 2017.

Clovis Torres

Secretary

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