What is the difference between high borosilicate glass and tempered glass

High borosilicate glass is a type of glass that is called high borosilicate glass due to its high boron content; Ordinary flat glass is sodium calcium silicate glass, which is basically free of boron

Tempered glass is a product obtained by reprocessing (or deep processing) ordinary flat glass, which has no comparability or mutual attribution with high borosilicate glass

But they all have a common characteristic: resistance to cold and hot shocks - rapid cooling and heating will not explode

The difference in the principle of obtaining this characteristic is vastly different: high borosilicate glass has a very low coefficient of thermal expansion due to the presence of boron in its chemical composition. When subjected to changes in temperature, it basically does not expand or contract, and naturally will not rupture due to uneven expansion or contraction; Tempered glass is made by the strong compressive stress formed on the surface of the glass after tempering treatment, which can counteract the adverse effects caused by surface expansion or contraction due to changes in temperature

Therefore, it is difficult to distinguish between the two in appearance