Tempered Glass

Tempered glass is produced by heating annealed glass in a furnace to 620掳C. Progressing from the furnace, the glass is rapidly cooled with jets of cold air, inducing compressive stresses to the surface while the center remains tensile. Stronger resistance to thermal breakage than annealed or heat strengthened glass. If breakage occurs the glass breaks up into small, cubical fragments, which are not threatening to humans.