Tempered  glass is a kind of prestressed glass, in order to improve the strength of glass, usually use chemical or physical methods, in the glass surface formation of compressive stress, glass bear external forces when the first offset surface stress, so as to improve the carrying capacity, enhance the glass itself resistance to wind pressure, heat and cold, impact.

The preparation process is obtained by cutting ordinary annealed glass into required size, heating it to about 700 degrees near the softening point, and then cooling it quickly and uniformly.

When the tempered glass is damaged by the impact of external forces, the glass is torn into small pieces at obtuse angles under the action of internal energy.Compared with the ordinary glass when broken, the large pieces are in the shape of long knife and sharp Angle, the small pieces after the broken tempered glass have little harm to the human body.