Herlambang B. Evaluation of Surface Roughness of ST-60 Steel Material After Turning Process With Variation of Rotation. PISTON J.Tech.Eng [Internet]. 2025 May 28 [cited 2026 Jan. 13];8(2):90-9. Available from: https://openjournal.unpam.ac.id/index.php/Piston/article/view/48933