FIELD: glass articles.
SUBSTANCE: invention relates to glass strengthening threads as components of composition that comprises the following components taken in limits determined below and expressed in weight %: SiO2, 58-62%; Al2O3, 10-16%; CaO, above 18%; MgO, above 1.5%; CaO + MgO, less 28%; Na2O + K2O + Li2O, less 2%; TiO2, less 1.5%; Fe2O3, less 0.5%; B2O3, less 2%; F2, less 2% being this composition comprises, except for, less 1% of other component(s) and above 0.5% of F2 or Li2O. Invention provides reducing price of composition and its retained technological effectiveness.
EFFECT: valuable properties of composition.
11 cl, 3 ex
