The final thesis describes the design of the welding technology for a 420kV tension part for traanssmision tower. The thesis consists of a theoretical part that describes the technologies and procedures used in the manufacture of the suspension, and a practical part with measurements and testing of the welded joint. The production of the tensiosn part for 420kV transmission tower is specified and described, including the product construction, material selection, material preparation, welding process, and testing. The purpose and history of the transmission tower are described in the thesis. The theoretical part discusses welding and its classification, a detailed description of MAG welding with its characteristics and parameters, and a description of the equipment and additional materials used. The second part of the thesis theoretically describes welding defects and their causes. It is followed by a theoretical description of non-destructive testing methods using magnetic particle and ultrasonic methods, as well as a theoretical description of destructive testing methods with additional descriptions of hardness measurement and macrostructure presentation of the weld. The experimental part of this thesis presents the preparation, technology, and production process of the product itself with the monitoring of welding parameters. It also includes the inspection of the weld using magnetic particle and ultrasonic methods, along with the measurement procedures and test results. Finally, the preparation of the sample, measurement procedure, and presentation of the weld's macrostructure and hardness with included test results.