Objective: to conduct comprehensive experimental studies of the impact toughness of 20GL cast steel, which is used for the manufacture of load-bearing parts of freight cars. To obtain a serial diagram of the dependence of the impact toughness value on the test temperature. Methods: the method of mechanical testing of cast steel specimens under impact loading was used, which allows obtaining quantitative estimates of the material’s ability to resist impact fracture at different temperatures (impact toughness tests). Micrographic analysis of the fracture surface was used to study the surface of impact fracture. Results: based on the results of tests of specimens made of 20GL cast steel, experimental dependences P = f (τ); E = f (τ) and a serial diagram (KCV — T) were constructed, which allow evaluating the performance of cast steel in the manufacture of load-bearing parts of cars for various climatic conditions of operation. Practical significance: the results obtained allow us to carry out work to improve the technological and service properties of cast load-bearing parts of freight cars.