## 5 Conclusions  
This study provides a comprehensive experimental comparison of three arc stud welding techniques--arc welding with a ceramic ferrule (ARC CF), arc welding with shielding gas (ARC SG), and arc welding assisted by a radially symmetric magnetic field (ARC SRM)--applied to structural steel (1.0038) and stainless steel (1.4301). Macrostructural examination, Vickers hardness testing, visual inspection, non-destructive testing, and mechanical bend tests were conducted to assess the quality and integrity of the welded joints under realistic conditions. The results demonstrate that the ARC CF process consistently produced the deepest weld penetration, reaching up to 3.547 mm in stainless-steel joints, which is advantageous for applications requiring high load-bearing capacity and robust joint strength. However, this method also tended to generate more molten metal spatter and irregular bead shapes, which may necessitate additional post-processing to achieve the desired surface finish. In contrast, the ARC SG technique achieved moderate penetration depths with stable fusion quality but was more susceptible to cold welds if the welding gun was not precisely aligned, highlighting the importance of careful parameter control. Among the three methods, the ARC SRM process resulted in the lowest penetration depths but produced the most uniform and symmetrical weld collars with minimal spatter and excellent visual appearance. This stable arc behavior and reduced heat input make the SRM technique particularly well suited for applications where minimal thermal distortion and high surface quality are required, such as in visible architectural joints or thin sheet assemblies. The hardness measurements confirmed that all three processes effectively increased the hardness of the weld metal relative to the base material, with ARC CF reaching the highest recorded value of 295 HV10, followed by ARC SRM and ARC SG. No evidence of undesirable brittle phases or unacceptable hardness gradients was found, indicating that the thermal cycles associated with stud welding were well controlled within acceptable limits. Non-destructive liquid penetrant testing, performed according to EN ISO 3452-1:2021, verified the absence of surface-breaking defects in all welded specimens. Combined with visual inspection and mechanical bend tests, these results confirm that all joints met the requirements of ISO 5817:2014 Quality Level C, demonstrating their suitability for general structural applications. From a practical perspective, the findings underline the need to manage molten metal spatter in ARC CF to ensure operator safety and minimize post-veld cleaning, and to mitigate arc blow effects in ARC SG to maintain consistent weld quality. The excellent arc stability and visual appearance achieved with ARC SRM suggest significant potential for its use in precision applications where minimal heat input and clean weld surfaces are critical. Overall, this comparative study offers valuable guidance for engineers and practitioners in selecting and optimizing stud welding techniques to balance mechanical performance, visual quality, and project-specific constraints. Future research should expand on these results by exploring high-strength and ultra-high-strength steels, refining SRM process parameters, and examining the long-term fatigue performance of stud welded joints under cyclic loading to further ensure structural safety and durability. Future research should extend to the following areas:  
* [noitemsep,topsep=0 pt]
* Stud welding of cold-formed high-strength and ultra-high-strength steels [5];
* Development of improved arc control devices and advanced process variants [5];
* Investigations into fatigue crack propagation under cyclic loads to ensure long-term joint performance and structural safety [39]. **Author Contributions:** Conceptualization, T.T. and T.M. ; methodology, T.T. ; software, T.T. ; validation, T.M. ; formal analysis, T.T. ; investigation, J.G. and L.V. ; resources, J.G. ; data curation, L.V.