X0508 4 2025-08-11 0 0000071829 NPK International Inc. NPKI 0001880836 Briggs Lori 9320 LAKESIDE BOULEVARD SUITE 100 THE WOODLANDS TX 77381 0 1 0 0 VP & President, Ind. Solutions 1 Common Stock 2025-08-11 4 S 0 8005 9.5125 D 252621 D The reported sale of 8,005 shares occurred automatically pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on March 11, 2025. The price reported is the weighted average price. These shares were sold in multiple transactions in the open market at prices ranging from $9.31 to $9.66, 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. By: M. Celeste Fruge For: Lori Briggs 2025-08-12