UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): February 25, 2020

HAYNES INTERNATIONAL, INC.

(Exact name of registrant as specified in
its charter)

Registrant’s telephone number, including area code: (765) 456-6000

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

¨       Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

¨       Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17CFR240.14a-12)

¨       Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17CFR240.14d-2(b))

¨       Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17CFR240.13e-4(c))

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company ¨

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. ¨

On January 15, 2020, upon recommendation of the Compensation Committee of the Board of Directors of Haynes International, Inc. (the “Company”), the Board of Directors of the Company approved the Haynes International, Inc. 2020 Incentive Compensation Plan (the “2020 Plan”), and submittal of the 2020 Plan to the stockholders for their consideration and approval. On February 25, 2020, at the Company’s 2020 annual meeting of stockholders, the stockholders of the Company approved the 2020 Plan. The terms and conditions of the 2020 Plan are described on pages 47 through 53 of the Company’s Definitive Proxy Statement on Schedule 14A filed with the Securities and Exchange Commission on January 24, 2020. This description is incorporated herein by reference and is qualified in its entirety by reference to the full text of the Plan, which was filed as Annex A to the Company’s Definitive Proxy Statement on Schedule 14A, is filed as an exhibit to this report, and is incorporated herein by reference.

On February 25, 2020, Haynes International, Inc. (the “Company”) held its annual meeting of stockholders. The following is a summary of the matters voted on at the meeting:

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 hereunto duly authorized.