(Mark One) ☒ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACTOF 1934 For the fiscal year endedMarch 31, 2026or ☐TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGEACT OF 1934 For the transition period from _____________ to ___________.Commission File Number 001-08462 GRAHAM CORPORATION (Exact name of Registrant as specified in its charter) Delaware16-1194720(State or other jurisdiction ofincorporation or organization)(I.R.S. EmployerIdentification No.)20 Florence Avenue, Batavia, New York14020(Address of principal executive offices)(Zip Code)Registrant's telephone number, including area code 585-343-2216 Securities registered pursuant to Section 12(b) of the Act: Securities registered pursuant to Section 12(g) of the Act: None Indicate by check mark if the Registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. YES☐NO☒ Indicate by check mark if the Registrant is not required to file reports pursuant to Section 13 or 15(d) of the Act. YES☐NO☒ Indicate by check mark whether the Registrant: (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of1934 during the preceding 12 months (or for such shorter period that the Registrant was required to file such reports), and (2) has been subject tosuch filing requirements for the past 90 days. YES☒NO☐ Indicate by check mark whether the Registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the Registrant was required tosubmit such files). YES☒NO☐ Indicate by check mark whether the Registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company,or an emerging growth company. See the definitions of"large accelerated filer,""accelerated filer,""smaller reporting company,"and"emerginggrowth company"in Rule 12b-2 of the Exchange Act. Large accelerated filer☐Non-accelerated filer☐Emerging growth company☐ Accelerated filer☒Smaller reporting company☐ If an emerging growth company, indicate by check mark if the Registrant has elected not to use the extended transition period for complying withany new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.☐ Indicate by checkmark whether the Registrant has filed a report on and attestation to its management’s assessment of the effectiveness of itsinternal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accountingfirm that prepared or issued its audit report.☒ If securities are registered pursuant to Section 12(b) of the Act, indicate by check mark whether the financial statements of the Registrant includedin the filing reflect the correction of an error to previously issued financial statements.☐ Indicate by check mark whether any of those error corrections are restatements that required a recovery analysis of incentive-based compensationreceived by any of the Registrant’s executive officers during the relevant recovery period pursuant to § 240.10D-1(b).☐ Indicate by checkmark whether the Registrant is a shell company (as defined in Rule 12b-2 of the Act). Yes☐No☒ The aggregate market value of the Registrant’s Common Stock held by non-affiliates of the Registrant, based on the closing price of the shares ofcommon stock on the NYSE Stock Market on September 30, 2025, was approximately $568.7 million. As of June 3, 2026, the number of shares of the Registrant’s Common Stock outstanding was 11,691,140 shares. DOCUMENTS INCORPORATED BY REFERENCE Portions of the Registrant's definitive Proxy Statement, to be filed in connection with the Registrant's 2026 Annual Meeting of Stockholders to beheld on August 25, 2026, are incorporated by reference into Part III, Items 10, 11, 12, 13 and 14 of this report. Table of Contents GRAHAM CORPORATIONAnnual Report on Form 10-KYear Ended March 31, 2026 PART I Cautionary Note Regarding Forward-Looking Statements2Item 1Business3Item 1ARisk Factors8Item 1BUnresolved Staff Comments22Item 1CCybersecurity22Item 2Properties24Item 3Legal Proceedings24Item 4Mine Safety Disclosures24 PART II Item 5Market for Registrant’s Common Equity, Related Stockholder Matters and Issuer Purchases of Equity Securities25Item 6Reserved25Item 7Management’s Discussion and Analysis of Financial Condition and Results of Operations26Item 7AQuantitative and Qualitative Disclosures About Market Risk38Item 8Financial Statements and Supplementary Data39Item 9Changes in and Disagreements with Accountants on Accounting and Financial Disclosure72Item 9AControls and Procedures72Item 9BOther Information74Item 9CDisclosure Regarding Foreign Jurisdictions That Prevent Inspections74 PART III Item 10Directors, Executive Officers and Corporate Gove