The diploma thesis deals with the problem of repair and renovation of the mold for production of precise aluminum castings with selected additional materials. The object of the research was selected materials that are used for repair in Nemak Slovakia. Since we have assumed, based on experience, that the available materials will not be suitable, we have also selected new hard metal materials that should meet the defined requirements. Three electrodes were used for the experiment using the ROZ method and 3 additional wires for the TIG method. As an essential requirement, we have chosen a hardness of over 50 HRC of repaired area. We also focused on using additive material without the need for pre-heating before welding. Since the wear of the mold at the repair site is abrasive, we wanted to use the carbide-tipped welds to extend the life of the mold between production cycles and thereby shorten the repair interval. By fulfilling the assignment, we would achieve dimensional stability for a longer period of time and thus contribute to higher productivity. In the practical part we evaluated the suitability of the tested materials for the experiment based on their achieved hardness. At the end we tested the selected additional wire and compared it with the previously used one in production conditions what we evaluated at the end of this thesis.