Results of Operations

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) August 11, 2025 L.B. Foster Company (Exact name of registrant as specified in its charter) Pennsylvania 000-10436 25-1324733 (State or other jurisdiction of incorporation) (Commission File Number) (I.R.S. Employer Identification No.) 415 Holiday Drive, Suite 100, 15220 Pittsburgh, Pennsylvania (Zip Code) (Address of principal executive offices) ( 412 ) 928-3400 (Registrant’s telephone number, including area code) Not Applicable (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 (see General Instruction A.2. below): ☐ 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, Par Value $0.01 FSTR Nasdaq Global Select Market 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 2.02     Results of Operations and Financial Condition On August 11, 2025, L.B. Foster Company (“Company”) issued a press release announcing the Company’s results of operations for the second quarter ended June 30, 2025. A copy of that press release is furnished with this report as Exhibit 99.1. The information contained in this Current Report shall not be deemed to be “filed” for the purposes of Section 18 of the Securities and Exchange Act of 1934, as amended, or otherwise subject to the liabilities of that section, nor shall such information be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, except as shall be expressly set forth by specific reference in such filing. Item 9.01     Financial Statements and Exhibits (d)    Exhibits See Exhibit Index below. Exhibit Index Exhibit Number Description *99.1 Press Release dated August 11, 2025 of L.B. Foster Company. *104 Cover Page Interactive Data File (embedded within the Inline XBRL document) *Exhibits marked with an asterisk are filed herewith. 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 hereunto duly authorized. L.B. FOSTER COMPANY (Registrant) Date: August 11, 2025 /s/ William M. Thalman William M. Thalman Executive Vice President and Chief Financial Officer (Duly Authorized Officer of Registrant)