The article shows the actuality of improving the hardening of loaded cylindrical gear teeth as well as reducing their cost. The analysis of modern methods of strengthening the teeth of loaded cylindrical gears is carried out. Both the advantages and disadvantages of these methods are shown. The possibilities of modern methods of metal surface hardening using laser radiation, including a scanning beam, are described. The main results of studying the influence of laser hardening conditions of 40X structural steel samples by a scanning laser beam on the hardness and roughness of the sample surfaces are presented. For typical operating conditions of motor and tractor transmission cylindrical gears, an assessment was made of the possibility of the necessary transmission life provision when using 40X structural steel for the manufacture of gears with subsequent hardening of the teeth with a scanning laser beam.