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UNITED STATES SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-K

(Mark One)

☒			Annual report pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

For the fiscal year ended December 31, 2020

OR

☐			Transition report pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

For the transition period from                      to                     

Commission file number 1-12001

Registrant’s telephone number, including area code: (412) 394-2800

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

Title of each class			Trading Symbol			Name of each exchange on which registered
Common stock, par value $0.10			ATI			New York Stock Exchange

Securities registered pursuant to Section 12(g) of the Act: None

Indicate by check mark whether the Registrant is 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 Section 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 of 1934 during the preceding 12 months, and (2) has been subject to such 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 Rule 405 of Regulation S-T (§ 232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit 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 definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company” and “emerging growth company” in Rule 12b-2 of the Exchange Act. (Check one): 

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.  ☐

Indicate by check mark whether the registrant has filed a report on and attestation to its management’s assessment of the effectiveness of its internal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issued its audit report. ☒

Indicate by check mark whether the Registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).    Yes  ☐   No  ☒

On February 5, 2021, the Registrant had outstanding 126,827,573 shares of its Common Stock.

The aggregate market value of the Registrant’s voting stock held by non-affiliates at June 30, 2020 was approximately $1.3 billion, based on the closing price per share of Common Stock on June 30, 2020 of $10.19 as reported on the New York Stock Exchange. Shares of Common Stock known by the Registrant to be beneficially owned by directors and officers of the Registrant subject to the reporting and other requirements of Section 16 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), are not included in the computation. The Registrant, however, has made no determination that such persons are “affiliates” within the meaning of Rule 12b-2 under the Exchange Act.

Documents Incorporated By Reference

Selected portions of the Proxy Statement for the Annual Meeting of Stockholders to be held on May 20, 2021 are incorporated by reference into Part III of this Report.

INDEX

			Page Number
PART I
Item 1. Business			3
Item 1A. Risk Factors			9
Item 1B. Unresolved Staff Comments			16
Item 2. Properties			16
Item 3. Legal Proceedings			16
Item 4. Mine Safety Disclosures			17
PART II
Item  5. Market for the Registrant’s Common Equity, Related Stockholder Matters and Issuer Purchases of Equity Securities			17
Item 6. Selected Financial Data			18
Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations			19
Item 7A. Quantitative and Qualitative Disclosures About Market Risk			47
Item 8. Financial Statements and Supplementary Data			49
Item 9. Changes in and Disagreements with Accountants on Accounting and Financial Disclosure			100
Item 9A. Controls and Procedures			101
Item 9B. Other Information			103
PART III
Item 10. Directors and Executive Officers of the Registrant			103
Item 11. Executive Compensation			103
Item 12. Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters			103
Item 13. Certain Relationships and Related Transactions, and Director Independence			104
Item 14. Principal Accountant Fees and Services			104
PART IV
Item 15. Exhibits, Financial Statements and Financial Statement Schedules			104
Item 16. Form 10-K Summary			106
SIGNATURES