Material event report (decision to redeem own convertible bonds early)

What happened

Material Event Report (Decision to Redeem Own Convertible Bonds Before Maturity) 6.0 Korea Advanced Materials Co., Ltd. Material event report / Matters subject to KRX reporting obligations To: Financial Services Commission / Korea Exchange July 27, 2026 Company name: Korea Advanced Materials Co., Ltd. Representative Director: Jo Heon-jeong Head office: 345 Cheomdangwagi-ro, Buk-gu, Gwangju Phone: 062-972-0116 Website: http://www.hankookam.com Preparer: (Title) Representative Director (Name) Jo Heon-jeong (Phone) 062-972-0116

Decision to Redeem Own Convertible Bonds Before Maturity 1. Type of bond: series 3, unregistered, interest-bearing, unsecured, privately placed convertible bonds 2. Bond issue date: June 10, 2026 3. Bond issue method: private placement 4. Bond maturity date: June 10, 2029 5. Face (electronically registered) amount of the bonds (KRW): 10,000,000,000 6. Face (electronically registered) amount to be acquired (KRW): 5,000,000,000 7. Acquisition decision date: July 27, 2026

8. Acquisition amount Amount (KRW): 5,000,000,000; basis: principal amount Expected payment date: August 4, 2026 Source of acquisition funds: other (offset against the subscription price for the 4th-series unregistered, interest-bearing, privately placed convertible bonds)

9. Acquisition method: over-the-counter acquisition 10. Reason for early acquisition before maturity: agreement with the bondholders 11. Future handling plan: retirement after redemption

12. Matters concerning conversion Conversion ratio: 100% Conversion price as of the report date (KRW/share): 5,604 Shares to be issued on conversion: Korea Advanced Materials Co., Ltd. registered common shares, 892,219 shares, 3.03% of total shares outstanding Conversion request period: June 10, 2027 to May 10, 2029

13. Face (electronically registered) balance remaining after acquisition (KRW): 5,000,000,000 14. Fair Trade Commission filing required: not applicable

15. Other matters of reference for investment decisions 1. This early acquisition before maturity concerns KRW 5,000,000,000 in face value, out of the Company's 3rd-series unregistered, interest-bearing, privately placed convertible bonds (total face value KRW 10,000,000,000), held by bondholders The Plus Associates Co., Ltd. and Kim Seong-hee, acquired by mutual agreement with the bondholders. 2. Source of acquisition funds and settlement method (offset): the acquisition price (KRW 5,000,000,000) will not be paid in cash separately but will instead be fully offset on the payment date against the subscription price (KRW 5,000,000,000) for the Company's newly issued 4th-series unregistered, interest-bearing, privately placed convertible bonds, treated as payment in kind. 3. Future handling: immediately upon completion of this early acquisition and offset settlement, the Company will apply to the Korea Securities Depository to cancel the electronic registration of the acquired 3rd-series bonds (KRW 500 million) and retire them in full. 4. Conversion-price adjustment on the existing 3rd-series convertible bonds: the conversion price (KRW 5,604) and expected conversion shares (892,219) stated in "12" above reflect the Company's 2-for-1 share consolidation (par value KRW 500 -> KRW 1,000), effective July 21, 2026, which doubled the original conversion price of KRW 2,802 and halved the original expected conversion shares of 1,784,439. 5. The "3.03%" ratio to total shares outstanding in "12" above is calculated using, as the denominator, the sum of the Company's total issued voting shares as of this report's filing date (28,541,299 shares, excluding 3,008 treasury shares) and the expected conversion shares for this 3rd-series CB (892,219 shares), i.e. 29,433,518 shares in total.

[Matters concerning the sellers] The Plus Associates Co., Ltd.: no special relationship with the Company or its largest shareholder; selected by mutual agreement for early acquisition before maturity; plans to subscribe for KRW 2,500,000,000 of the 4th-series CB; face amount of bonds sold: KRW 2,500,000,000; note: refinancing offset. Kim Seong-hee: no special relationship with the Company or its largest shareholder; selected by mutual agreement for early acquisition before maturity; plans to subscribe for KRW 2,500,000,000 of the 4th-series CB; face amount of bonds sold: KRW 2,500,000,000; note: refinancing offset.

[Matters concerning sellers that are a corporation or organization] (1) Basic information: The Plus Associates Co., Ltd.; number of investors: 2; representative director An Eun-cheol (67.00% stake); managing member An Eun-cheol (67.00% stake). (2) Key financial matters for the most recent settlement period (unit: KRW million), fiscal year 2025 (settled December): total assets 2,949; sales 84; total liabilities 2,699; net income 18; total equity 250; external auditor: none; capital stock 100; audit opinion: none.