What Is Tempered Glass?
Jun 30, 2022
When traditional sheets of glass break, they can become very dangerous They break into large shards with razor-sharp edges which can easily cut or severely injure someone And since these sheets of glass aren’t very strong, this can be a major safety concern for vehicle windows, slippery bathroom spaces, and high-rise buildings Luckily, there is an answer Tempered glass is stronger and breaks into smaller pieces, making it a safer option for all of the scenarios mentioned above
In this article
What is tempered glass?
Tempered glass is a form of glass that is stronger than typical annealed glass and breaks into smaller pieces Also known as safety glass, tempered glass is heated and cooled in specific ways to increase its strength and change its composition
To truly understand tempered glass, it’s important to be familiar with annealed glass Annealed glass, also known as standard float glass, is glass that has gone through a cooling treatment on a factory’s float line After pouring and floating atop a tin bath, annealed glass is cooled very slowly to prevent internal stress
Tempered glass is annealed glass that receives a heat treatment to harden and strengthen it, increasing its strength up to four times Instead of breaking into large, dangerous shards, tempered glass “spider webs” when it breaks The entire pane fractures into small pieces with smoother edges, meaning there is significantly less chance of causing an injury
How is tempered glass made?
Glass manufacturers make tempered glass by heating and then cooling annealed glass The process creates tension and compression in the glass that makes it stronger but also causes the glass to shatter into small, less-dangerous pieces
The first step in making toughened glass via tempering is to start with a piece of annealed glass that is already cut to the exact size and shape necessary Then, the manufacturer heats the annealed glass in a tempering oven until it reaches temperatures over 1,000 degrees Fahrenheit At that point, the exterior of the glass is cooled rapidly with high-pressure air
While the exterior surface of the glass is cooling quickly, the manufacturing process prevents the interior from cooling as quickly The inside of the glass cools slower and begins to pull on the outer layers This creates tension inside the glass while the outer surface experiences compression—opposing forces that increase the glass’s strength
This tempering process also causes the glass to shatter into small, rounded pieces when broken For this reason, it’s impossible to cut and snap sheets of tempered glass as they will shatter completely
How is tempered glass used?
Due to its safer shattering nature, tempered glass has a lot of practical uses Essentially, any large sheet of glass that could break and cause injury will typically be safety or tempered glass Also, any piece of glass that must be strong enough to resist breaking due to impacts should also be tempered It’s also used in high-heat situations
- Electrionics Tempered glass is widely used in hand-held electronic applications including screens on tablets and smartphones These devices often fall, and users sometimes sit on them, requiring the glass screen to be much stronger and safer than typical annealed glass
- Cars There are also automotive uses for tempered glass