Tempered Glass is also known as toughened glass; it is four to five times stronger than Annealed Glass of the same size and thickness and is resistant to any kind of thermal breakage.
Tempered Glass is formed when Annealed Glass goes through a chemical and heated process of tempering. Annealed Glass is passed through a furnace at 700 degree Fahrenheit and then cooled rapidly, as a result the outer surface of the glass goes into compression and the inner surface of the glass goes into tension. The Physical properties of glass which include colour, clarity, transmission of light and chemical composition remain unchanged.
When toughened glass breaks it forms tiny fragments which are less likely to injure anyone instead of large glass chunks.
Toughened glass finds its applications in areas where there is high risk of contact and breakage. It is used in curtain walling, large panels of window glass, frameless doors, front and rear windows of cars.
The main disadvantage of Tempered Glass is that once glass is toughened it cannot be reworked on, all required holes have to be drilled or sizing has to be done before the tempering process.