Toughened glass (also known as tempered glass) can be up to five times stronger than normal glass. This is produced from annealed glass which is heated and rapidly cooled which introduces stress into the structure of the glass which results in it being strengthened. This significantly increases its resistance to most mechanical and thermal stress, thus making it ideally suited for architectural metalwork structural glazing systems, where the glass is to be bolt or clamp fixed and also where the glass is to be exposed to extreme temperatures. If broken, toughened glass will disintegrate into small fragments with dulled edges, which is less likely to cause serious injury.
Tempered glass is about five times stronger than “ordinary,” or annealed, glass. And unlike annealed glass, which can shatter into jagged shards when broken,tempered glass fractures into small, relatively harmless pieces.