After the toughened glass is broken, the fragments will break into uniform small particles and there is no sharp corner like a common glass knife. Therefore, it is called safety glass and is widely used in automobiles, interior decoration and high-rise windows. Usually, after ordinary glass is broken, the sharp knife shaped sharp corner is easy to cut children or colliders, causing personal injury. The main difference between tempered glass and ordinary glass is whether the glass becomes small particles or knife shape after breaking. However, in the process I inspection, it is undoubtedly unrealistic to use this destructive inspection. So how can we know whether the self C bought tempered glass? This has to be analyzed from the manufacturing principle of tempered glass. Tempered glass is obtained by cutting ordinary annealed glass into the required size, heating it to a near softening point, and then cooling it quickly and evenly. After tempering, the glass surface forms uniform compressive stress, while the interior forms tensile stress, which greatly improves the performance of slope glass. The tensile strength is more than 3 times that of the latter and the impact resistance is more than 5 times that of the latter. It is precisely because of this feature that the stress feature has become an important sign to identify the true tempered glass, that is, the tempered glass can see color stripes at the edge of the glass through the polarizer, and black and white spots can be seen on the surface of the glass. Polarizer can be found in camera lens or glasses. Pay attention to the adjustment of light source during observation, so it is easier to observe that the bending strength of tempered glass is 4 ~ 5 times that of ordinary glass. The bending strength of 5mm thick tempered glass can usually reach 152mpa. The impact strength is about 1.53 ~ 3 times that of ordinary glass in China and about 4 times that of ordinary glass in foreign countries. For example, 227g steel ball glass sample (300x300x5mm) falls freely at a height of 2.5 ~ 3M above the center without breaking, while the glass is usually broken below 1m. The deflection of tempered glass is 3 ~ 4 times larger than that of ordinary glass. A 1200X 350x 6mm tempered glass has a maximum bending strength of 100mm. Tempered glass has a certain water pressure resistance.