What Is Tempered Glass? Can It Be Used for Security?

By December 18, 2021 May 8th, 2023 Blog, Uncategorized

Tempered glass is one of the most commonly used types of glass for commercial applications.


It has unique properties that make it a better choice for commercial properties than standard annealed glass, but it should not be confused with security glass. 


What Is Tempered Glass?


Tempered glass, also known as tempered safety glass, is a special type of toughened glass. During the manufacturing process, the glass gets heated, or tempered, which changes the physical properties of the glass.


The glass tempering process compresses the outer surfaces of the glass, while putting the inside layers into tension. This makes it so that, when the glass breaks, it crumbles into thousands of small, granular chunks.


This is why tempered glass is a type of safety glass. Whereas standard window glass breaks apart into sharp, jagged shards that can easily cause serious injury, tempered safety glass breaks in such a way that it is relatively harmless.


Tempered glass vs. annealed glass


Standard modern window glass is called annealed glass. Though heating and cooling are part of the process of making any type of glass, annealed glass doesn’t receive the same type of heat treatment as tempered safety glass.


Because of the unique heat strengthening process that tempered window glass goes through, it is approximately 4 times stronger than most annealed glass. 


Despite this, tempered windows cannot be considered impact-resistant windows — they are just a bit tougher than standard window glass.


When annealed glass breaks due to an impact, the sharp shards of glass can fly dangerously inwards, potentially injuring anyone on the other side of the glass. It is also much less safe to clean up and dispose of than tempered shards of glass.


What is tempered glass used for?


Because of its unique properties, tempered glass is used wherever human safety is a big concern. 


A very common application that you’re probably familiar with is for car windshields and windows. In fact, you’ve probably walked by a car that’s been broken into (hopefully not yours) and seen all those little cubes of glass on the ground, right? Well, that’s tempered car window glass.


If we were to use standard annealed glass on vehicles, even a minor car accident could cause anyone in the car major injury. With tempered car glass, drivers and passengers are less likely to get hurt in a minor crash that causes the windows to break.


Tempered glass is also commonly used for:


  • Retail storefront windows
  • Offices (windows, doors, and glass walls/partitions)
  • Glass entry doors
  • Shower and tub enclosures
  • Glass furniture
  • Refrigerator shelves
  • Glass dishware and kitchenware
  • Architectural glass


Tempered Glass vs. Security Glass


Though they are both types of strengthened glass, tempered and security glass have little more in common.


By now you know that tempered glass is NOT designed to be impact resistant. Security glass, on the other hand, is designed specifically to resist various types of impacts to improve security.


There are many different types of security glass, or glazing, each with their own unique compositions and characteristics. 


In general, you can put any type of security glazing into one of the two following two categories:


  1. Containment-grade (non-ballistic) glazing
  2. Ballistic-grade (bullet-resistant) glazing


Which of these categories a sheet of security glass falls into depends entirely on the types of impacts it is built to resist. 


For instance, containment-grade glazing sheets do not stop any bullets, but they can withstand high-force impacts of many other types.


Ballistic-grade glazing, on the other hand, is rated to withstand a number of rounds of a specific caliber/weight, fired from a certain type of firearm.


For comparison, tempered glass is not designed to withstand high-force impacts at all. Remember that it is intended for the sole purpose of increasing human safety where it is used.


What is security glazing used for?


Security glazing is used to protect properties and people against a wide range of threats, including those from mother nature and from other people.


For example, luxury retailers can retrofit their storefront windows and display cases with some type of security glass to protect against vandalism, burglary, smash-and-grab theft, and rioting and looting.


Though tempered glass is also commonly used for commercial windows, remember that it doesn’t do anything to protect against threats like those we just mentioned. In other words, a burglar with a hammer can smash through a tempered retail window with no problems.


Here are some other common reasons to use security glazing:


  • Storm damage mitigation (especially in hurricane zones)
  • Active shooter protection


Types of commercial properties that can benefit from a security glass retrofit include:


  • High-end retail stores
  • Schools and universities
  • Government buildings
  • Office buildings
  • Places of worship/spiritual centers
  • Banks and other financial institutions
  • 24-hour convenience stores
  • Cash transaction windows
  • Detention centers
  • Hospitals/psychiatric facilities
  • Hospitality businesses


Can you use tempered glass and security glass together?


Yes, tempered safety glass and security glazing can be used in tandem to make your commercial windows incredibly safe and secure.


Certain types of security glazing, such as our Riot Glass® RG series and ArmorPlast® AP lines, are designed specifically to be retrofitted into or onto your existing windows, protecting the glass behind.



So, if you already have tempered storefront windows, for example you can over glaze (mount on the outside) security glass to add a virtually invisible protective barrier that protects the existing glass from breaking.


Then, if the security glazing receives enough high-force impacts or gets penetrated by bullets, the tempered safety glass behind will break apart safely, instead of flying dangerously inwards in sharp, jagged pieces.


Now That You Know What Tempered Glass Is…


You should have a better understanding of what tempered window glass is for. You should also know that, if your goal is to increase your property’s security, you need to use some type of security glazing in addition to or instead of tempered safety glass.


Riot Glass specializes in laminated security glass and polycarbonate glazing shield retrofits. Contact us today for more information about our products or to schedule a consultation.