Fully tempered glass is approximately four times stronger than annealed glass of the same thickness and configuration. Residual surface compression must be over 10,000 PSI for 6mm glass, according to ASTM C 1048
When broken, it will break into many relatively small fragments, which are less likely to cause serious injury. The typical process to produce tempered glass involves heating the glass to over 1,000 degrees F, then rapidly cooling to lock the glass surfaces in a state of compression and the core in a state of tension, as shown in the diagram
Tempered glass is often referred to as â??safety glass,â?� because it meets the requirements of the various code organizations. This type of glass is intended for general glazing, and safety glazing such as sliding doors, storm doors, building entrances, bath and shower enclosures, interior partitions, and other uses requiring superior strength and safety properties.