Material Agreement, Financial Obligation (Form 8-K)

On September 19, 2025, ATI Specialty Materials, LLC (the "Company"), an indirect wholly-owned subsidiary of ATI Inc. ("ATI"), entered into a three-year, $125 million accounts receivable securitization facility (the "Facility") pursuant to (i) a First Tier Purchase and Sale Agreement (the "First Tier Agreement") among the Company, as Servicer and as the Originator, and ATI Securitization Holdings LLC, a bankruptcy-remote special purpose entity that is a direct wholly-owned subsidiary of the Company ("Holdings"), as Buyer, (ii) a Second Tier Purchase and Sale and Agreement (the "Second Tier Agreement") among the Company, as Servicer, Holdings, as Seller, and ATI Securitization LLC, a bankruptcy-remote special purpose entity that is a direct wholly-owned subsidiary of Holdings (the "SPE"), and (iii) a Receivables Purchase and Financing Agreement (the "Receivables Purchase and Financing Agreement" and, together with the First Tier Agreement and the Second Tier Agreement, the "Agreements") among the SPE, the Company, as Servicer (the "Servicer"), the purchaser/lenders that are parties thereto from time to time (collectively, the "Purchaser/Lenders"), and PNC Bank, National Association, as Administrative Agent (the "Administrative Agent"), and PNC Capital Markets LLC, as Structuring Agent.

Under the Agreements, the Originator has sold or contributed, and will continue to sell or contribute on an ongoing basis, certain of its receivables, to Holdings which, in turn, has sold or contributed, and will continue to sell or contribute, all such receivables to the SPE. The SPE may borrow and incur indebtedness from, and/or sell receivables to, the Purchaser/Lenders in an amount not to exceed $125 million in the aggregate.

Amounts outstanding under the Receivables Purchase and Financing Agreement accrue interest based on either the forward-looking term rate based on the secured overnight financing rate as administered by the Federal Reserve Bank of New York ("SOFR Rate") for a one-monthperiod or the daily SOFR Rate for a period of one month as of the date of incurrence, as selected by the SPE. The Agreements include customary fees, conditions, representations and warranties, indemnification provisions, covenants and events of default. Receivables in the Facility are subject to certain criteria, limits and reserves.

As of September 25, 2025, approximately $80 million of loans and/or investments were outstanding under the Facility. The Facility has a three-year term.

Certain of the Secured Parties and their affiliates have provided and may, from time to time, continue to provide investment banking, financial advisory, lending and/or commercial banking services to ATI, the Company and their affiliates, for which they have received, and may in the future receive, customary compensation and reimbursement of expenses.

Arrangement of a Registrant.

The disclosure set forth in Item 1.01 of this Current Report is incorporated by reference into this Item 2.03.