is more resistant to thermal stress than annealed glass. It can withstand differences in temperature of approximately 100°C
more resistant to breakage due to bending (70 N/mm²) than annealed glass
breaks into large sharp pieces which can cause injury
Accordingly, heat-strengthened glasses are not safety glasses. Heat-strengthened glasses break in a crazed pattern.
Magnetron coatings which can be thermally treated must be heat strengthened to achieve the stated performance (fragmentation, optical, Ug value)
The light, thermal and energy performance of thermally toughened glasses is exactly the same as that of the same annealed glass.
Finishing
Edge finishing The following edge finishings are available for heat-strengthened glasses:
Arrissed edges
Ground edges but some bright areas permitted
Ground edges but – no bright areas
Polished edges
For buildings, the heat-strengthened glass will be supplied as standard with arrissed edges but depending on the requirements of the particular application, a different finish may be possible. Ground polished edges are normally only destined for nonbuilding applications.
