Advantages:
The term toughened glass is generally used to describe fully tempered glass but is sometimes used to describe heat strengthened glass as both types undergo a thermal 'toughening' process.
There are two main types of heat treated glass, heat strengthened and fully tempered. Heat strengthened glass is twice as strong as annealed glass whilst 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 MPa while Heat Strengthened glass is between 40 and 55 MPa.
It is important to note that while the strength of the glass does not change the deflection, being stronger means that it can deflect more before breaking. Annealed glass deflects less than tempered glass under the same load, all else being equal.
