Tempered glass is made from normal annealed glass via a thermal tempering process in which the glass is subjected to heat till its softening point and then rapidly cooled. This gives the glass its strength 4 to 5 time compare to normal glass.

Toughened Glass is four to five times stronger than its equivalent thickness of normal annealed float sheet glass.

Tempered glass provides greater thermal strength. It offers increased resistance to both sudden temperature changes and temperature differentials up to 240°C compared to normal annealed glass which can withstand temperature differentials up to 40°C only.

Toughened glass is very difficult to break but even on breakage it will break into small, relatively harmless fragments. This substantially reduces the likelihood of injury to people as there are no jagged edges or sharp corners which are normal in the case of breakages of annealed glass. It is considered as a safety glazing.