Ati Inc

ATI Inc. is a Delaware corporation with its corporate headquarters located at 2021 McKinney Avenue, Suite 1100, Dallas, TX 75201, telephone number (800) 289-7454, Internet website address www.atimaterials.com. Our Internet website and content contained therein or connected thereto are not intended to incorporate into this Annual Report on Form 10-K. References to "ATI," the "Company," "the Registrant," "we," "our" and "us" and similar terms mean ATI Inc. and its subsidiaries, unless the context otherwise requires.

When used in this Annual Report on Form 10-K, unless the context otherwise requires or unless otherwise specified, any reference to "year" is to the Company’s fiscal year. The Company follows a 4-4-5 or 5-4-4 fiscal calendar, whereby each fiscal quarter consists of thirteen weeks grouped into two four-week months and one five-week month, and its fiscal year ends on the Sunday closest to December 31. Fiscal years 2025, 2024 and 2023 ended on December 28, 2025, December 29, 2024, and December 31, 2023, respectively. All fiscal years presented include 52 weeks of operations.

ATI produces specialty materials, highly differentiated by our materials science expertise and advanced process technologies. Our mission is to solve the world’s challenges through materials science. Aerospace & defense, our largest end markets, represent approximately 68% of total sales, led by products for jet engines and airframes in addition to a wide range of defense applications. Additionally, we have a strong presence the specialty energy market and also serve customers in several other markets including conventional energy, medical, electronics and other industrial markets.

We operate in two business segments: High Performance Materials & Components (HPMC) and Advanced Alloys & Solutions (AA&S). HPMC produces a wide range of high performance materials, components, and advanced metallic powder alloys. These products are made from nickel-based alloys and superalloys, titanium and titanium-based alloys, and a variety of other specialty materials. HPMC’s capabilities range from cast/wrought and powder alloy development to production of highly engineered finished components, and 3D-printed aerospace products. The HPMC segment’s primary focus is on maximizing jet engine materials and components growth, with approximately 92% of its revenue derived from the aerospace & defense markets, including nearly 68% from products for commercial jet engines. Commercial aerospace products have been the main source of sales and EBITDA growth for HPMC over the last several years and are expected to continue to drive HPMC and overall ATI results in the future. HPMC has also experienced strong growth in defense products, with fiscal year 2025 sales growth of 24%. Sales of defense products comprise almost 11% of HPMC's total sales.