Statement of Changes in Beneficial Ownership (Form 4)

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b). Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person * Briggs Lori 2. Issuer Name and Ticker or Trading Symbol NPK International Inc. [NPKI] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner __X__ Officer (give title below) _____ Other (specify below) VP & President, Ind. Solutions (Last) (First) (Middle) 9320 LAKESIDE BOULEVARD, SUITE 100 3. Date of Earliest Transaction (Month/Day/Year) 06/01/2026 (Street) THE WOODLANDS, TX 77381 4. If Amendment, Date Original Filed (Month/Day/Year) 6. Individual or Joint/Group Filing (Check Applicable Line) _X_ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person (City) (State) (Zip) Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned

1.Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 06/01/2026 F 5,401(1) D $14.31 257,950 D Common Stock 06/01/2026 F 9,577(1) D $14.31 248,373 D Common Stock 06/01/2026 F 6,777(1) D $14.31 241,596 D Common Stock 06/01/2026 M 24,340 A $ 0 (2) 265,936 D Common Stock 06/02/2026 S 10,446(3) D $14.5776(4) 255,490 D

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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 3)

2. Conversion or Exercise Price of Derivative Security

3. Transaction Date (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

4. Transaction Code (Instr. 8)

5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5)

6. Date Exercisable and Expiration Date (Month/Day/Year)

7. Title and Amount of Underlying Securities (Instr. 3 and 4)

8. Price of Derivative Security (Instr. 5)

9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)

10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)

11. Nature of Indirect Beneficial Ownership (Instr. 4)

Code

V

(A)

(D)

Date Exercisable

Expiration Date

Title

Amount or Number of Shares

Restricted Stock Units

$ 0 (2)

06/01/2026

M

24,340

(5)

(5)

Common Stock

24,340

$ 0

0

D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Briggs Lori 9320 LAKESIDE BOULEVARD SUITE 100 THE WOODLANDS, TX 77381			VP & President, Ind. Solutions

Signatures

By: M. Celeste Fruge For: Lori Briggs		06/03/2026
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 4(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	Represents shares withheld to satisfy tax withholding obligations upon the vesting of restricted stock units.
(2)	The restricted stock units vest and convert into shares on a one-for-one basis.
(3)	The reported sale of 10,446 shares occurred automatically pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on December 15, 2025.
(4)	The price reported is the weighted average price. These shares were sold in multiple transactions in the open market at prices ranging from $14.33 to $14.74, inclusive. The reporting person undertakes to provide to NPK International Inc., any security holder of NPK International Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in footnote (2) to this Form 4.
(5)	Grant of restricted stock units that vest in one-third increments on June 1 of each subsequent year after grant and settle in shares.

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