Tempered glass has high strength. Glass debris will be broken into uniform small particles and without sharp corners as knife after broken. So tempered glass is called safety glass and widely used for room decoration. Generally speaking, the small particles of ordinary glass with sharp corner is easily to hurt children. The mainly method to distinguish is that get small particles or knife shaps after broken.
Using this destructive testing is not realistic in the engineering test. How to know whether it is tempered glass or not? We must analysis from the manufacturing principle of tempered glass. Tempered glass is cut with require size and then heated to close softening point. Certainly it should be fast and uniform cooling to get tempered glass. Glass surface will form uniform pressure after tempering treatment. But the internal form tension and make glass performance improved greatly. The tensile strength is three times of the latter and the impact strength is five times more than the latter. So the stress characteristics has became an important symbol to distinguish the true and false of tempered glass. Tempered glass can see the color stripe on the edge of glass through a polarizing plate. We also can see black and white spots from the glass surface. Polarized light sheet can be found in camera lens. At the same time, you should pay attention to light source adjustment in order to observation easily.
