Due to the fragmentation of tempered glass, the fragments will break into uniform small particles and do not have common glass knife like sharp corners, making it known as safety glass and widely used in automobiles and interior decoration.
In home settings, the sharp knife like corners of ordinary glass that have been broken can easily cut children or colliders, causing personal injury. The main difference between tempered glass and ordinary glass is whether it becomes small particles or knife shaped after being broken. However, in engineering inspection, it is undoubtedly unrealistic to use such destructive testing.
So how can one know if the one they bought is tempered glass?
This also needs to be analyzed from the manufacturing principle of tempered glass, which is obtained by cutting ordinary annealed glass into the required size, heating it to a near softening point, and then rapidly and evenly cooling it. After tempering, uniform compressive stress is formed on the surface of the glass, while tensile stress is formed inside, greatly improving the performance of the glass. The tensile strength is more than three times that of the latter, and the impact resistance is more than five times that of the latter.
It is precisely this characteristic that stress characteristics become an important indicator for distinguishing true and false tempered glass. Tempered glass can see colored stripes at the edges of the glass through a polarizing light plate, while on the surface layer of the glass, black and white spots can be seen. Polarizing lenses can be found in camera lenses or glasses. When observing, pay attention to adjusting the light source for easier observation.