NPK International Inc.

Item 2.02 Results of Operations and Financial Condition. On July 29, 2026, NPK International Inc. (the “Company”) issued a press release announcing financial information for the three and six months ended June 30, 2026. The press release is attached to this Current Report on Form 8-K as Exhibit 99.1 and is incorporated herein by reference. The information in Item 2.02 of this Current Report on Form 8-K and the information in the exhibit attached hereto shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act except as expressly set forth by specific reference in such filing. Use of Non-GAAP Financial Information To help understand the Company’s financial performance, the Company has supplemented its financial results that it provides in accordance with generally accepted accounting principles (“GAAP”) with non-GAAP financial measures. Such financial measures include Adjusted Income (Loss) from Continuing Operations, Adjusted Income (Loss) from Continuing Operations Per Common Share, earnings before interest, taxes, depreciation and amortization (“EBITDA”) from Continuing Operations, Adjusted EBITDA from Continuing Operations, Adjusted EBITDA Margin from Continuing Operations, and Free Cash Flow. We believe these non-GAAP financial measures are frequently used by investors, securities analysts and other parties in the evaluation of our performance and liquidity with that of other companies in our industry. Management uses these measures to evaluate our operating performance, liquidity and capital structure. In addition, our incentive compensation plan measures performance based on our consolidated EBITDA, along with other factors. The methods we use to produce these non-GAAP financial measures may differ from methods used by other companies. These measures should be considered in addition to, not as a substitute for, financial measures prepared in accordance with GAAP. Applicable reconciliations to the nearest GAAP financial measure of each non-GAAP financial measure are included in the attached Exhibit 99.1.