In this study, it was aimed to recycle waste polystyrene (PS) and obtain a material with high screw retention resistance that can be used instead of wood material. For this purpose, waste MDF dust (MF) and glass fiber (GF) were used as fillers in the PS matrix. Waste PS was first dissolved in gasoline and then 50-100-150 % fillers were added and mixed manually. To solidify the mixture, it was kept in the oven at 100 degrees for 30 minutes. Additionally, the samples were subjected to heat treatment by keeping them in the oven at 190 degrees for 30 minutes. Thus, the effect of heat treatment on the samples was also examined. The samples were kept in water for 2 hours and 24 hours and their thickness swelling (TS) and water absorption (WA) were determined. For mechanical characterization, the screw withdrawal resistances (SR) of the samples were analyzed. The results were analyzed using the SPSS package program. According to the obtained results, it was determined that there was no significant change in the amount of TS as the MF was increased, but the amount of WA has increased. It was determined that GF filling swelled less than MF. But WA was more than MF. Apart from the addition of 150 % GF, fillers increased the densities. SR resistance increased with the addition of filler. While heat treatment did not change the physical properties of the samples significantly, it increased the SR resistance. As a result, waste PS can be recycled into a material with high SR by adding waste MF and GF and can be used instead of wood material.