YUNHONG GREEN CTI LTD.

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): September 29, 2026

YUNHONG GREEN CTI LTD.

(Exact name of registrant as specified in its charter)

22160 N. Pepper Road, Lake Barrington, IL 60010

(Address of principal executive offices) (Zip Code)

(847) 382-1000

(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):

Securities registered pursuant to Section 12(b) of the Act:

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 September 29, 2026, Yunhong Green CTI Ltd. (the “Company”) entered into a Conversion Restriction and Waiver Agreement (each, an “Agreement”) with each of (i) Wickbur Holdings LLC, the holder of all 130,000 outstanding shares of the Company’s Series E Convertible Preferred Stock and Common Stock Purchase Warrant No. E-1, and (ii) Agile Wisdom International Limited, the holder of all 70,000 outstanding shares of the Company’s Series F Convertible Preferred Stock and Common Stock Purchase Warrant No. F-1 (each, a “Holder”; such preferred stock, the “Preferred Stock”; and such warrants, the “Warrants”). The Company entered into the Agreements in connection with a proposed public offering of its Common Stock (the “Offering”).

Under each Agreement, the Holder has agreed not to convert its Preferred Stock, exercise its Warrant, or transfer either, other than to a permitted transferee that agrees to be bound by the Agreement, during a restricted period. The restricted period continues until 61 days after the Holder delivers written notice of termination, which the Holder may not deliver before the later of (i) the final closing or abandonment of the Offering and (ii) the second anniversary of the Agreement.

Each Holder has consented to the Offering under the applicable stock purchase agreement (each, a “Purchase Agreement”) and certificate of designation and has waived its piggyback registration rights with respect to the Offering. The Company has waived its right to require exercise of the Warrants during the restricted period. The Series F Agreement also prohibits the payment of dividends on the Series F Preferred Stock in shares of Common Stock during the restricted period.

The Agreements also amend the Purchase Agreements to conform the conversion provisions of the Preferred Stock to the applicable certificate of designation. Each Holder has released any claim arising from the conversion provisions previously stated in the applicable Purchase Agreement.

As consideration for the Holders’ agreements, the Company extended the expiration date of each Warrant from March 11, 2027 to March 11, 2029.

The foregoing description of the Agreements does not purport to be complete and is qualified in its entirety by reference to the full text of the Agreements.

On October 1, 2026, the Board of Directors of the Company fixed December 30, 2026 as the date of the Company’s 2026