Glass produced by this special process has enhanced strength and is used mainly for rear and side windows of vehicles.
Tempered glass is produced by heating glass to near bending point (approx. 650℃) and rapidly cooling the surface uniformly with air.
When the glass is subjected to tensile force, the force is counteracted by the surface compressive stress. Tempered glass is three to five times stronger than ordinary glass at the same thickness.
It has the characteristic of shattering instantly if broken into small 'nuggets'. As there are no sharp, knife-like shards, it is unlikely to cause serious injury, so this is why tempered glass is also known as safety glass.