Two types of heat treated glass

Now then, there are two main types of heat treated glass. heat strengthened and fully tempered. Now those sound like some pretty complicated things, but fear not, I’m here to explain them.

First let’s start with Heat strengthened Glass:

Heat strengthened glass is twice as strong as annealed glass. The heat puts the molecules under pressure and this makes the glass much stronger.

Fully tempered glass is typically four to six times the strength of annealed glass and withstands heating in microwave ovens. The difference is the residual stress in the edge and glass surface. Fully tempered glass in the US is generally above 65 Mega Pascal while Heat Strengthened glass is between 40 and 55 Mega Pascal.