Shahandzir Baharom creator author. text my 2025 2025 monographic eng xvii, 142 pages : illustrations (some color) ; 30 cm. + 1 CD-COM Metalworking fluids (MWFs) are crucial for cooling and lubricating metal workpieces, enhancing quality by reducing heat and friction. However, conventional MWFs, usually mineral oil-based, cause environmental pollution and health risks due to poor biodegradability and high recycling costs. Researchers are exploring biodegradable alternatives like vegetable based MWFs. Lubricant performance is evaluated using methods such as chip formation analysis with a Quick Stop Device (QSD), which freezes chips to assess their properties without alteration. Oblique cutting tests compare lubricants for machinability performance. Experimental investigation using Bintangor laut oil and synthetic ester, among others, during turning stainless steel AISI 316L, demonstrates promising results. Minimum Quantity Lubrication (MQL) emerges as a better alternative to flood coolant systems. Orthogonal cutting analysis reveals that synthetic ester (SE) achieves the best performance in terms of cutting force (> 20%), chip thickness (> 16%), and tool-chip contact length (> 26%) compared to dry cutting. However, Refined Bleached and Deodorized Palm Olein (RBDPO) exhibits competitive performance. In oblique cutting tests, bio-based lubricants demonstrate acceptable values for cutting forces, chip thickness, and tool wear. Despite its good cutting performance, RBDPO produces high roughness (> 60%) compared to SE on the workpiece surfaces. The results highlight the potential of Crude Jatropha Oil (CJO) as a promising alternative lubricant, with opportunities for further enhancement through chemical modifications like esterification and additive enrichment to improve tribological and physical properties. specialized Shahandzir Bin Baharom Faculty of Manufacturing and Mechatronic Engineering Technology Thesis (Master of Science) -- Universiti Malaysia Pahang – 2025 Includes bibliographical references Faculty of Manufacturing and Mechatronic Engineering Technology Dissertations Universities and colleges Dissertations Theses Dissertations THE0010077 (Local) UMPSA 250516 20251125111041.0 eng