Tempered glass that is heated and then cooled rapidly several times to make it stronger than annealed glass. Tempered glass is safer than annealed glass because when it is broken it falls into pebble-like pieces without sharp edges.

Tempered glass is a toughened safety glass, which is produced by heating annealed glass in a furnace to at 620 degrees. After the furnace, the glass is rapidly cooled with jets of cold air, inducing compressive stresses to the surface while the center remains tensile. It is able to resist approximately a five times higher impact than normal glass.