Heat-strengthened glass is the glass achieved as the result of cyclic process of its sharp heating and cooling that makes the glass two times solid than the raw one of the same thickness and configuration. The heat-strengthened glass takes a load according to the standard EN 1863.
The heat-strengthened glass takes higher thermal loads and pressure. However in case of destruction the debris of such glass are bigger than of the tempered one and as a rule, they do not come apart but stay in the frame.
The heat-strengthened glass is not deemed safe and cannot be used where the requirements of safe glazing must be met. However, thermostrengthening efficiently helps to cope with temperature difference and wind loads. Remember that such a glass cannot be drilled or cut, engraved or treated in the sandblast method. The glass sheet may be broken.