Both tempered glass (FT glass) and heat-strengthened glass (HS glass) are called heat treated glass. They are both produced in the same tempering furnace in a similar way.
Whether FT glass or HS glass, glass is heated beyond its softening point 600℃, the the only difference in the process used to create FT glass and HS glass is the rate of cooling.
In the process of tempered glass, glass is cooled rapidly creating a higher surface compression and edge compression in the glass. This compression make the tempered glass 4 to 5 times as strong as regular annealed glass of the same thickness. When broken, tempered glass will shatter into small granular chunks instead of splintering into jagged shards as ordinary annealed glass does. So tempered glass is a type of safety glass.
However, in the process of heat strengthened glass, it undergoes a slower cooling process than tempered glass resulting in a lower compression strength. Heat strengthened glass is approximately twice as strong as regular annealed glass of the same thickness. It breaks, like regular annealed glass, into relatively large pieces that will tend to remain in the glazing system.
Recommended application of fully-tempered glass:
- For Locations where safety glass is required by law or code;
- Where human impact is a concern;
- Where maximum resistance to impact or load is required;
Recommended application of heat-strengthened glass:
- For locations where drop of glass fragments in the event of breakage is a
Concern;
- For locations where mechanical strength is required, but no need strong impact resistance, like glass canopy.
