PURPOSE: To enable low temp. welding and to fill a vacancy or a magnetic head or the like with this glass so that the production yield of magnetic heads is improved by specifying the amt. of SiO2, PbO, ZrO2, B2O3, ZnO, Al2O3, etc.

CONSTITUTION: This low temp. welding glass compsn. has a compsn. containing, by wt.%, 6-8% SiO2, 57-62% PbO, 1.5-2% ZrO2, 4-6% B2O3, 1-2.5% ZnO, 2-5% Al2O3, 20-25% Tl2O3, 1-2% SrO. When this glass compsn. is used for the production process of a magnetic head, the reaction with alloy films can be suppressed and chipping of glass can be decreased, which improves magnetic characteristics. This compsn. has good wettability and excellent welding property, so that it suppresses thermal deformation of a substrate or peeling of thin alloy films.