When glass is tempered, it is heated in an oven close to its melting point (approximately 650-700 °C depending of the thickness), after which it is quickly cooled.
With tempering, the glazing’s resistance against shocks, bending, high temperatures (max 300 °C) and quick temperature changes is enhanced.
Tempered glass breaks into small pieces with mostly blunt edges.
Since tempered glass can no longer be cut, drilled or ground after tempering, it needs to be cut and worked (possible openings, holes, grindings) into its final measurements and shape prior to tempering. Also the manufacturer or product name as well as the possible standard number are marked permanently into the glazing during the tempering phase.