How Is Tempered Glass Made and Is It Good for Security?

Tempered glass, also known as safety glass, is something that commonly gets confused with security glass. We’re here to help clear up some of the misconceptions about this type of glass and answer some of the questions we often hear at Riot Glass. By the end of this article, you’ll have a better understanding of exactly what tempered safety glass is, how to tell if glass has been tempered, its uses, and how it’s different from the types of security glass that we offer and recommend for increasing your property’s security.

What Is Tempered Glass?

In short, tempered glass is a type of toughened safety glass that has been heat-treated to make it stronger and safer than standard window glass.

How Is Tempered Glass Made?

During the manufacturing process, this type of glass is heated up intensely in a special tempering oven, then cooled down with a special quenching procedure that cools down the exterior surfaces of the glass much quicker than the center. This forces the exterior surfaces to compress, which gives the glass its strength. 

Before a glass is passed through a tempering oven, it is thoroughly inspected for imperfections that could cause it to break during the tempering process. Once the glass has been approved for tempering, it goes into the oven and gets heated up to above 600 degrees Celsius (1112 degrees Fahrenheit). When the glass comes out of the oven, it is immediately blasted with high-pressure air from different nozzles pointed at the glass from all angles to quench it. Some glass is also tempered using a chemical treatment, but it is much more expensive than using a tempering oven and quenching the glass with air, so it is not as common.

Regular glass differs from tempered glass because it is cooled down using an annealing process, which is slower than quenching. This different cooling process makes standard glass significantly weaker than tempered glass. In fact, tempered safety glass is about 4x stronger than traditional glass. One of the major differences between tempered glass and regular glass, as you may have seen at one point or another, is that standard glass breaks apart very easily into large, jagged, sharp shards. Safety glass, on the other hand, shatters into tons of tiny little square shards that are relatively harmless.

Another big difference in the manufacturing processes for traditional glass sheets and tempered glass sheets is when they get cut. Standard glass can be cut, drilled, shaped, and totally customized after it has been fabricated and annealed. However, tempered glass must be cut and shaped to the desired size before it goes into the tempering oven and gets quenched. If you try to cut or drill tempered safety glass after it’s been toughened, it will just break apart.

How to Tell if Glass Is Tempered

One of the telltale signs of glass that has been tempered is that tempered glass sheets have smooth edges. This is because they are sanded and washed before the glass is tempered to remove the sharpness, unlike traditional glass sheets that still have sharp corners and edges. Another sign of glass that has been tempered is that you can easily see surface imperfections on the glass. Also, if you look at the glass through polarized glasses, you will be able to see dark lines and spots on the glass. Finally, the surefire way of knowing whether a piece of glass is tempered is to watch it break and see if it shatters into tons of tiny square shards.

Signs that glass has been tempered:

• There are visible imperfections on the surfaces
• It has smooth edges
• You can see black spots and lines through polarized lenses
• The glass shatters into little squares when broken

Can I Use Tempered Glass for Security?

Though it is stronger and safer than standard window glass, tempered glass is not recommended for security applications. A determined intruder will have no difficulty smashing right through tempered glass panels and gaining entry to your business. If you have ever seen a car with a smashed out window, well, that’s tempered glass—it doesn’t seem very secure, does it?

Tempered safety glass is safer than standard window glass, which is why it’s common applications include things like automobile side and rear glass, shower and tub enclosure glass, and patio furniture. For these types of applications, when the main goal is avoiding injury caused by sharp broken glass, tempered safety glass makes perfect sense. However, it is not an effective security solution when your concern is to protect your business against things like forced entry, burglary, smash-and-grab theft, rioting, looting, vandalism, storm damage, ballistic attacks, or bomb blasts.

What you can use to increase the security of your glass doors and windows is security glass, which can refer to a range of products, including security window films, laminated security glass, and polycarbonate panels. All these types of custom glass security products can help protect your business against man-made and natural threats, to varying degrees. For example, security window film can delay would-be intruders by up to about 3 minutes. In contrast, polycarbonate panels are virtually unbreakable and can even stop bullets, keeping bad guys and their guns outside at all times.

Choose Riot Glass Security Glass for Business Security

Riot Glass offers a full range of security glass products for commercial clients. Our team of security professionals is dedicated to helping you choose and install the right security glass for your goals and budget. Whether you want to secure your business against forced entry and burglary, fortify your property against storm damage, or protect against ballistic attacks and bomb blasts, we can help. We are happy to schedule a consultation with one of our security experts who can conduct a threat assessment of your property and provide security recommendations.

Contact us today for more information about our Riot Glass Window Security Laminates, Riot Glass laminated security glass, and ArmorPlast polycarbonate unbreakable glass shields.