Safety VS Tempered Glass


Safety vs. tempered glass Although both are considered ‘safer’ because they have been manufactured for strength and, if damaged, to not shatter into sharp shards, there is a difference both in the manufacture and performance of safety and tempered glass.

Safety glass was first invented early in the 20th century by a French scientist. Today the process used is essentially the same, where two pieces of sheet or plate glass are bonded together with a layer in between them, which is usually plastic. This lamination keeps the glass from shattering and is why it is used for car windshields.

Conversely, tempered glass is found in the passenger and rear windows of a car, as well as many other applications. In the tempering process, the annealed glass is heated in a furnace past its ‘annealing point,’ then immediately cooled down with air jets. This forces the surface to quickly become cool and stiff, while the core of the glass, because it is still much hotter, takes longer to cool down and finally harden.

And that is what improves the strength of the tempered glass. If the surface receives any stress, it does not carry through to the core of the glass, so a crack is unable to form. If the glass does receive damage, it shatters into small cubes rather than sharp shards.