Heat strengthened glasses are also resistant to external loads and thermal stresses like fully tempered glasses. Heat strengthening is performed in the same furnaces and at the same tempereatures as in full tempering. The major difference is the cooling rate of the glass. The breakage pattern is different than fully tempered glass. The fragmaents are much bigger. The principle of the pattern is that each crack should end at the periphery of the window and there shouldn’t be a free part likely to fall. Therefore, the risk of falling glass is very low due to the edges of the broken parts are stuck on the frame. It has lower impact resistance than fully tempered glass but has great tendency on facade designs due to its higher visual quality. The r

Resistance to sudden temperature changes (thermal schock resistance) is 100 °C. Another advantage of heat strengthened glass is that it has no risk of unexpected spontaneous breakages due to NiS particles. The heat soak test which is essential to fully tempered glass is not necessary for heat strengthened glass.