Metal injection molding (MIM) is a proven technology for fabricating complex geometry and low-cost components. The binder system formulation and powder loading are the key parameters affecting the final properties of the manufactured parts in this process. This study investigates the influence of palm stearin (PS) content in a PS/High-Density Polyethylene (HDPE) binder system for three powder loadings of 60, 65, and 70 Vol.%. The manufactured feedstocks are characterized using scanning electron micrograph (SEM), thermo gravimetric analysis (TGA), and differential scanning calorimeter (DSC), rheological and mechanical tests. The results show that PS enhances mechanical properties at increased powder loading. In addition, residual carbon following changing the PS percentages has a significant role in determining the final characteristics of parts. Findings demonstrated that PS could drastically alter the rheological behavior, a crucial criterion for optimizing the feedstock formulation in the MIM process.