In this book states that due to special thermal cyclic treatment (TCT) performed in the range of relatively low annealing temperatures it is possible to modify morphology and space distribution of carbides phase, thus, to eliminate or considerably reduce carbide inhomogeneity in tool steels. As a result there is a structural condition of metal built up, with optimum allocation of carbides by morphology and sizes that favorably influences during further hot and cold plastic deformation, hardening heat treatment.