Due to their improved mechanical characteristics, epoxy nanocomposites based on glass wool fiber have attracted a lot of interest in a variety of technical applications. In this experiment, tensile and flexural behavior of glass wool fiber-based epoxy nanocomposites, as well as their density and thermal expansion parameters, are examined. Glass wool fibers and an epoxy matrix containing nanoparticles were used to create the composites. Mechanical characteristics were tested using tensile and flexural techniques, while density measurements and thermal expansion studies were used to determine dimensional stability. Results showed that the addition of glass wool fibers and nanoparticles greatly enhanced the nanocomposites’ tensile and flexural strength. When glass wool fibers were added to composites, density rose. Also modified was the materials’ thermal expansion behavior, with the nanocomposites displaying lower thermal expansion than neat epoxy. These results shed light on the mechanical performance and thermal characteristics of epoxy nanocomposites based on glass wool fiber, a key ingredient in the creation of cutting-edge materials for use in engineering.