As a result of the development of additive manufacturing technology and the decrease in device and filament costs, 3D printers have become widespread. The transition from prototype to final product production with a 3D printer is possible by increasing product strength. In many studies where production is carried out with the Fused Filament Fabrication (FFF), it is seen that Polylactic Acid (PLA) or Acrylonitrile Butadiene Styrene(ABS) filaments are used. In addition, infill geometry and infill density properties have been examined with limited materials in the literature. The research aims to increase product performance by examining the effects of infill pattern and infill density with different filaments. In this study, in order to investigate the mechanical properties of the product printed with FFF, samples were produced with 2 different infill patterns and 2 different infill densities using 5 different filaments and the tensile test results were examined. As the results, the samples with linear infill pattern and 60% infill density showed the highest strength for PLA, ABS, STH, PETG and Semiflex filaments. The optimum infill pattern was found to be “linear.” As infill density increased, tensile strength increased by 4.6% for Semiflex, 5.66% for PLA, 9% for ABS, and 11% for STH.