Company Update

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): July 18, 2025 AMPCO-PITTSBURGH CORPORATION (Exact name of Registrant as Specified in Its Charter)   Pennsylvania 1-898 25-1117717 (State or Other Jurisdiction of Incorporation) (Commission File Number) (IRS Employer Identification No.) 726 Bell Avenue Suite 301 Carnegie , Pennsylvania 15106 (Address of Principal Executive Offices) (Zip Code) Registrant’s Telephone Number, Including Area Code: 412 456-4400   (Former Name or Former Address, if Changed Since Last Report) 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 (17 CFR 240.14a-12) ☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c)) Securities registered pursuant to Section 12(b) of the Act: Title of each class Trading Symbol(s) Name of each exchange on which registered Common Stock, $1 par value AP New York Stock Exchange Series A Warrants to purchase shares of Common Stock AP WS NYSE American LLC 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. ☐ Item 8.01 Other Events. On July 18, 2025, Ampco-Pittsburgh Corporation (the “Corporation”) issued a press release with a reminder to warrant holders that the Company’s publicly traded warrants to purchase common stock are set to expire on August 1, 2025 (the “Expiration Date”). The New York Stock Exchange (NYSE) has notified the Corporation that it will suspend trading in the warrants on the NYSE American prior to the opening of trading on July 31, 2025 to permit trades to settle in time for any final exercises prior to the Expiration Date. A copy of the Company’s press release is attached as Exhibit 99.1 to this Form 8-K and is incorporated herein by reference. Item 9.01. Financial Statements and Exhibits. (d) Exhibits. Exhibit Number Description 99.1 Press Release dated July 18, 2025 104 Cover Page Interactive Data File (embedded within the Inline XBRL document).   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. AMPCO-PITTSBURGH CORPORATION Date: July 18, 2025 By: /s/ Michael G. McAuley Michael G. McAuley Senior Vice President, Chief Financial Officer   and Treasurer