1. The character of the heating curves for the central zone of a sample is determined only by the chemical composition of the steel and the position of the selected temperature of the medium in relation to point Ai for the steel to be heated. The other parameters produce an effect only on the length of the individual stages and the total duration of heating. 2. Owing to the non-synchronous development of the pearlite-austenite transformation along the sample cross-section, the regular heating conditions in the central zone of the sample become disrupted long before the temperature in this zone attains the A1 point, and the transformation within the entire sample volume extends over a considerable period of time. 3. The length of the individual heating periods, as well as the total duration of the sample heating to the temperature of the bath, are related to the characteristic size of the sample V/F, expressing the ratio of its volume to the surface τ=a(V/F)b. The value of coefficient a is determined by the shape of the sample, its initial temperature, and the selected heating temperature. The value of factor b depends entirely on the material of the sample and ranges from 1.2 to 1.27. 4. The heating time for steel cylinders and spheres in the salt bath may be calculated with the aid of the proposed nomograph.