The aim of this work is to analyse the possibility to increase the service life of working parts on construction machinery exposed to intensive wear, such as steel blades of the rotary device for roadside vegetation maintenance and grass cutting. A special attention is paid to characteristic working conditions and complex wear mechanisms. In order to select the most appropriate reparation technology, both model and real investigations were conducted. The aim of the model investigations was to select the most appropriate procedure, filler materials and hard facing technology. Worn cutting edges of the blades were hard faced and sharpened by grinding to the shape and dimensions of new blades. Then, both new and repaired blades were alternately mounted on the rotor of the machine. Their wear was monitored under the same working and weather conditions. The repaired blades have proven more resistant to wear than the new ones, which is due to better properties of the hard faced layers.