... 620°C. Progressing from the furnace, the glass is rapidly cooled with jets of cold air, inducing compressive stresses to ... thermal breakage than annealed or heat strengthened glass If breakage occurs the glass breaks up into small, cubical fragments, ... windows, doors, shopfronts in offices, houses, shops etc. Interior glass screens, partitions, balustrades etc. Shop display windows, showcases, display ...