You may have heard about tempered glass and how it’s majorly used in smartphone screens. But what lies behind it? Indeed, tempered glass is manufactured uniquely hence the reason it is used in special functionalities.

During manufacturing, the glass undergoes strong heat before being cooled off rapidly. The process leaves the glass with a special structure that can be used for even greater functionality.

The preceding stage is called the tempering process. Here, the glass sheets are passed on a heating machine or an oven under high temperatures either in batches or in a continual manner.

The final stage in the manufacture of tempered glass is called ‘quenching’, which involves cooling down. A high-pressure air blast is blown on the surface of the glass through various novels. As the central part of the glass contracts, the outer sections flatten as a result of the pressure. This way, tempered glass sheets undergo a longer cooling process as compared to the standard glass sheets leaving them much stronger and safer.

Where is Tempered Glass often Used?

The strength and durability of tempered glass make it best suited for several uses that include:

  • Screen protectors.
  • Bathroom windows.
  • Microwave dishes and basking ovens as they withstand high temperatures.
  • Vehicle windows.
  • Buildings, glass doors, escalators, glass chairs and tables, staircase, and solar panels.
  • Phone booths.

How to Identify Tempered Glass

To the eyes of a newbie, a tempered glass may seem just similar to ordinary glass.
However, identifying tempered glass doesn’t require any super ordinary skills. With a few tricks that are covered here, you’ll be well set to identify a tempered glass.

Check the Edges

Tempered glass often gets the final strong finish because of the extra processing it goes through. Such glass sheets are sandblasted and cooled gradually resulting in soft and even edges. On the other hand, standard glass comes out as rough because of limited processing.

Therefore, if you have access to the edges, feel the texture. A soft touch will imply that a glass is tempered while a rough texture implies the opposite.

Identify Visible Imperfections

Look at the surface of the glass. Does it have any scratches? Does it have a slight bending or are there some distortions? If so, then the glass is most likely to be tempered. This is because tempered glass undergoes a rigorous process in its manufacture. The extreme heat alters the structure of the glass and when removed from the furnace using tongs, some marks remain on its surface. Furthermore, some small particles of the machine rollers can remain stuck even after normal cleanups.

Examine the Glass through Polarized Glasses

Another effective way of finding out whether a glass is tempered or not is to look at it through polarized glass. Under direct sunlight, put on polarized sunglasses or place polarized glasses in between your eyes and the glass. A tempered glass often has spots across the surface or dark shady lines. The view is formed during the tempering process by the machine rollers. At times, tempered glass may need an even closer look through the polarized glasses to observe the difference.

Impossible to Drill

While this is not a widely known fact, it is impossible to drill through tempered glass sheets. The enhanced manufacturing process makes the structure of the glass prone to breakage during drilling. It is for this reason that making shapes or cutting holes is done before the tempering process.

Check the Glass Corners for a Bug

The mentioned ‘bug’ means a mark or sandblasted symbol. Such figures, which are left by the manufacturer, act as proof that a given glass is tempered and is often represented through the mark of the manufacturer and CPC standards.
If you buy tempered glass from the manufacturer, you will easily see the logo on the sheet. If a tempered glass is not sourced from the manufacturer, it is necessary to take a closer look for concealed logos. If you cannot see the sign, chances are high that you were tricked into buying an ordinary glass (unless you specifically asked the manufacturer, for design purpose, to remove the logo).

Draw a Line

Before getting started with this technique, we recommend that you proceed with it only if you had planned to cut the glass. Furthermore, if the glass gets tempered, seek the help of professionals.

To proceed with this step, find a glass cutter. This tool is available in most hardware stores. Draw a line on the surface of the glass where you want to cut the glass. If it’s bumpy on the course of cutting, it means that the glass is tempered. However, if it maintains a clean line, then you are most likely handling an annealed glass.

Tempered Glass is Ideal for Safety

There is a contradicting difference in the way tempered and annealed glass sheets break. While tempered glass breaks uniquely into small and non-dangerous pieces, annealed glass breaks unevenly and spreads into harmful pieces. This is the reason why tempered glass is often preferred for safety purposes and used in areas where human safety is crucial.

Why Should I Opt for Tempered Glasses?

Tempered glass is five times stronger compared to annealed glass. They possess great temperature tolerance, which is the main reason why they are used as mobile protectors. A tempered glass is not prone to scratches or damages, making it great for house interiors and use in gadgets. During breakage, tempered glass poses the least threat for injury.


Buying undesired glass type is costly. You risk exposing your gadgets to easy theft and having your interiors undesirably decorated. What’s more, you expose people to injury in case of an accident.

The tips discussed above will assist you to determine the originality of tempered glass and hence avoid sellers who want to trick you into buying annealed glass as tempered glass. The information guarantees that you get value for money by buying the right glass for the right purpose.