Fully Tempered Glass "popularly known as toughened glass" is made of annealed glass. It is 4 to 5 times stronger than an annealed glass & twice stronger than a heat strengthened glass.On breaking a Fully Tempered Glass shatters in to small size oval shaped pieces having blunt edges thus reducing possibility of human injury to a big extent. It is widely used where human safety is concerned.
The fully tempered glass is heated to its softening point temperature of 600 - 700 degree celsius then it is moved for quenching. The quenching begins at a glass temperature of 400 - 500 degree. The quenching causes compression on 20 percent surface area of glass and edges remaining 60 percent middle part develops stress zones as a result glass becomes stronger on surface and edges providing freedom to applicators for end to end fixing of glass using spider fittings or other accessories used for glass glazing.For a fully tempered 6 mm thick glass the minimum surface compression is 10000 psi.