The given article contains consideration of process of production and operation glass-mould. Also described the main reasons for decrease in firmness of the operation glass-moulds. The microstructure of preform is investigated at layer-by-layer and traditional hardenings of castings. Con- trol of phase composition of cast iron and formation of separate structural components in the course of hardening of castings allows to provide the increased heat resistance and heat conductivity to details of glass-moulds. In presented article described influence of each structural component on the complex of properties of details working in the conditions of cyclic thermal loadings and abrasive wear.