1. The use of HTTMT and vacuum melting increases the resistance of steel to brittle fracture and lowers the cold brittleness threshold, while increasing the work of crack propagation. 2. After HTTMT the highest strength of vacuum heats is about 240 kg/mm2 at which the steel retains more or less satisfactory values of ductility and plasticity. After SHT of open heats this same strength is approximately 180 kg/mm2. 3. We found no advantage of LTTMT over such a simple method of increasing the strength as increasing the carbon concentration (by about 0.1%).