## 4 Conclusions  
Based on the results of the performed experiments, several conclusions can be drawn regarding the effect of pressure or holding pressure on the tensile strength limit and porosity of castings produced in the pressure casting process:  
* The experiments showed that higher values of holding pressure can have both positive and negative effects. On the positive side, higher holding pressure can improve the filling of castings by reducing the amount of air trapped in the casting, leading to a decrease in porosity. This results in an overall increase in the quality of the internal structure of the castings. However, it was observed that higher holding pressure values can also lead to a shorter life of the mold and increased downtime during the pressure casting process. * The experiments revealed that higher pressure values can lead to an undesirable condition where the mold is slightly opened with subsequent injection in the parting plane during the pressing process. This indicates that excessively high-pressure values can cause mold-related issues and affect the integrity of the castings. * The research findings establish a clear connection between the chosen technological parameters, i.e., pressure or holding pressure, and the resulting mechanical properties and quality of the castings produced in the pressure casting process. Measured tensile strength values and porosity values are largely related. * The monitored technological parameters--pressure or pressure in the mold cavity together with the closely related temperature conditions in the pressure casting--are among the basic factors that affect the quality of the final casting. * In addition to pressure or holding pressure, other parameters such as injection speed, melt temperature, and cooling can also influence the resulting properties of the castings. In the conducted experiments, these parameters were kept constant to isolate the specific effect of pressure or holding pressure on the castings. However, it is important to note that in real production scenarios, these parameters would typically vary, and their interaction with pressure or holding pressure may affect the final quality of the castings. * The effect of ideal input conditions on the final quality of castings cannot be definitively determined in a general sense. The impact may vary depending on the specific casting design, material, and production environment. Therefore, it is essential to conduct comprehensive studies and experiments, considering various process parameters, to understand their individual and combined effects on the resulting properties and quality of the castings. The influence of technological parameters, such as pressure or holding pressure, on the final mechanical properties of castings and the inner structure is consistent with the findings of other researchers in the field of die casting [13; 14; 32]. This indicates a common understanding and agreement on the impact of these parameters on the quality of castings. Increasing the holding pressure consistently leads to a decrease in the percentage share of porosity in castings. This correlation highlights the importance of pressure control in minimizing porosity and improving the overall quality of the castings. From the comparison of the conducted research, conclusions can be drawn that:  
* Measured values are specific and valid for the selected combination of technological parameters and selected material, and, when evaluating the results, it is necessary to consider the testing conditions and the possible occurrence of errors. * The achieved results can serve as a foundation for the technical preparation of casting production. They provide valuable insights for optimizing the properties and quality of castings. These results can be used as a starting point for determining the appropriate values of the examined technological parameters based on the quality requirements of specific types of castings.