The research work is focused on the application of 3D printing in the field of development and production of prototype car parts. Within the experiments are performed static tests of tensile strength of standardized test specimens printed on two different FDM 3D printers from selected PLA filament material. The experiments were performed on two different universal testing machines with a mechanical and video extensometer in order to obtain the values of actual stresses depending on the relative elongation of the working areas of the test specimens. The results of the work are 3D printed parts of the car safety restraint system designed in the SolidWorks software. Specifically, it is about 3D printed parts of a seat belt lock for a passenger car. The Original Prusa i3 MK3S and German RepRap X400 PRO v3 3D printers are used. The standard ISO 527-2 shape type 1B is used. The temperature settings are that the nozzle temperature is 215 °C and the heated bed temperature is 60 °C. The fill is set to 100 % at a 45° angle for tensile tests by machines Shimadzu Autograph AG-X plus 5kN with accessory TRViewX and Zwick Z030.

Acknowledgement: The work was made possible thanks to the financial support of the Cultural and Educational Grant Agency of the Slovak Republic (KEGA) under grant KEGA 001TnUAD-4/2025 and the Scientific Grant Agency of the Slovak Republic (VEGA) under grant VEGA 1/0289/25.