The increase in the volume of plastic waste in Indonesia, which reaches approximately 64 million metric tons per year, coupled with a still-low recycling rate, underscores the need to repurpose High-Density Polyethylene (HDPE) plastic waste into products with both practical and economic value. This study aims to design and fabricate a laboratory-scale hexagonal injection molding die as part of an effort to convert recycled HDPE plastic waste into decorative products, as well as to analyze the molding process and evaluate the quality of the resulting products based on their shape, dimensions, and surface condition. The research methodology involved several stages concept selection using the Pugh method, detailed product design, determination of the planning basis and selection of machine components, structural strength analysis of the mold, and the fabrication and testing of the mold on an injection molding machine. The results of the study show that the mold design developed using low-carbon steel with three cavities is capable of producing hexagonal products in accordance with the design dimensions, namely a hexagonal size of 50.00 mm with a mold depth of 5 mm, as well as a material capacity of 29.24 grams for the three cavities. The molded products demonstrated geometric conformity with the initial design, although the surface quality still showed a level of smoothness that was not entirely uniform and has the potential for further improvement through process parameter optimization in future research. This study is expected to serve as a reference in the development of laboratory-scale injection molding designs and to support efforts to manage HDPE plastic waste into products with both practical and economic value.