NPK International Inc.

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A

PROXY STATEMENT PURSUANT TO SECTION 14(a) of THE SECURITIES EXCHANGE ACT OF 1934 (Amendment No. )

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Filed by a Party other than the Registrant [ ]

Check the appropriate box:

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Payment of Filing Fee (Check all boxes that apply):

NOTICE OF ANNUAL MEETING AND PROXY STATEMENT

2026 Annual Meeting of Stockholders

May 20, 2026

April 9, 2026

Dear Fellow Stockholder:

On behalf of the Board of Directors, you are cordially invited to attend the 2026 Annual Meeting of Stockholders of NPK International Inc. (the “Company”), which will be held on Wednesday, May 20, 2026, at 9:00 a.m., Central Daylight Time, at the NPK Headquarters, located at 9320 Lakeside Boulevard, Suite 100, The Woodlands, TX 77381(the “Annual Meeting”). In the following pages, you will find the Notice of Annual Meeting of Stockholders as well as a Proxy Statement describing the business to be conducted at the meeting.

Whether or not you plan to attend the Annual Meeting in person, it is important that you study carefully the information provided in the accompanying Proxy Statement and vote. Please promptly vote your shares by telephone, by the Internet or, if the Proxy Statement was mailed to you, by marking, signing, dating and returning the proxy card in the prepaid envelope so that your shares can be voted in accordance with your wishes.

Thank you for your continued support.

Sincerely,

Matthew S. Lanigan

President and Chief Executive Officer

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