Tempered Glass

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We may not think too often about the glass that surrounds us. For example, when is the last time you looked up at a bank of office windows and wondered how shatter-resistant they were? Thankfully, tempered glass is everywhere we look, even if we don’t know it. You may not think about this type of glass often, but when you want to make some changes in your home or office, tempered glass is the way to create beautiful, safe designs for your space and everyone in it.

What Is Tempered Glass?


Tempered glass – also called safety glass or toughened glass – is an extra-strong type of safety glass. The process of tempering glass dates back to the late 1800s when nearly molten glass was dipped into heated oil.

The tempering process doesn’t mean that the glass won’t break – just that it breaks differently. If you’ve ever seen the small, uniformly sized pieces of a broken car window or a shattered cellphone screen, then you’ve seen the difference between tempered glass and the large shards that occur when standard annealed glass breaks.

This type of glass is also much clearer than annealed glass. Standard clear glass comes with a slightly green tint to it that you might not notice until you see it against a white wall.

Customizing this type of glass for whatever application you need is easy. With this glass, you can:

  • Tint it with color (usually grey or bronze)
  • Choose a custom thickness
  • Design a specific shape
  • Choose the type of finished edge

With each design decision, it’s important to keep in mind that this glass cannot be changed once it’s tempered. All cuts and holes for any hardware must be done before the tempering process occurs.

How Is Tempered Glass Made?


Tempered glass is made in a chemical or thermal process that actually changes the physical structure of the glass. This process places the inside of the glass in a state of tension (pushing out), while the outside is in a state of compression (pushing in). These two forces work with each other to create glass that is four times stronger than regular glass.

  • To get this balance of tension and compression, annealed glass is pushed through a roller table
  • The glass is heated to just about 1200 degrees
  • The outside of the glass is then rapidly air-cooled
  • The center of the glass remains somewhat fluid as the outside cools
  • This quick cooling period locks the glass’s balance between pushing out and pressing in
  • For chemically created glass, a 0.1 mm thickness of glass at the surface exchanges its sodium ions for potassium ions. This exchange is conducted in a molten bath of potassium nitrate. This exchange creates an even stronger piece of glass than thermal tempering.

Both thermal and chemical tempering results in remarkably tough glass.

What Is Tempered Glass Used For?


Tempered glass is best used in any of the following three situations:

  1. Where safety is paramount
  2. Where local codes require it
  3. Where glass must be resistant to high or rapidly changing temperatures

Of course, safety in the home is important everywhere, but there are some cases where broken glass could be especially dangerous. The kitchen and bathroom are two places in the home where accidents are most likely to occur, so it’s no surprise that this type of glass is often used in these areas.

Tempered glass can be found around the home in various places, including:

M&M Glass has a wide variety of glass projects for you to find your inspiration from.

FAQs About Tempered Glass


M&M Glass gets a lot of questions about glass. We’ve covered some of them below, but always feel free to reach out to our team if you have more questions. We're always here to answer questions you have about your family's safety.  


Is tempered glass breakable?

Tempered glass is breakable, but it’s how it breaks that matters. Instead of crashing into large, jagged pieces or lethal slivers, this glass breaks into relatively small but uniform shapes.


Is tempered glass scratch-proof?

If you press the surface of any glass hard enough, you will leave a scratch. That said, it is scratch-resistant and keeps its high polish longer than thinner annealed glass.


How can you tell if glass is tempered?

You can recognize tempered glass if:

  1. There is a sandblasted tempering mark (also called a bug and optional for many custom pieces)
  2. The edges of the glass are smooth (never jagged, sharp, or rough)


If you are not planning on using a piece of glass and you want to know if it has been tempered, score a line with a glass-cutting tool. The annealed glass will cut cleanly, but tempered glass will flake or create a bumpy line.


How to clean tempered glass?

Cleaning this kind of glass is simple, but it’s important to understand what you can and cannot use. In general:

  • Avoid abrasive cleaners
  • Never use vinegar
  • Clean with a soft cloth (no deep scrubbing)

For frequent cleaning, simply use your favorite glass cleaner and a soft microfiber cloth to remove smudges, fingerprints, and dust.

If your glass tabletop, glass shelves, or glass shower doors become cloudy, add a few more steps to your process.

  1. Mix dish soap and water in a spray bottle
  2. Spray the entire surface and let it sit (this gives the cleaner time to break down dirt and oil)
  3. Using a sponge, wipe gently until all the cleaner is removed
  4. Use a clean, soft cloth or another sponge and polish until the surface is dry


If you prefer to use a commercial glass shower cleaner, double-check to be sure it’s safe for tempered glass.

Using a squeegee on your glass shower after every use prevents build-up. Make sure to clean up spills on tabletops and glass shelves as they happen, too.


Where can I find tempered glass cut to size? 

Because tempered glass cannot be drilled, polished, or cut, all measurements and fittings must be done before the glass is tempered. If you want your glass cut to size, it’s best to measure twice – because you can only cut once. This is why it’s crucial to work with a custom glass company that has experience with glass projects.

M&M Glass has been providing residential and commercial customers in the Baton Rouge, New Orleans, North Shore, and Lafayette communities with beautiful, durable custom-cut glass pieces for almost 40 years.

Find Custom Tempered Glass In Louisiana


When you are looking for custom glass in Louisiana, we hope you’ll give M&M Glass a call. Our process starts with a no-obligation, free consultation. For clients who aren’t quite sure where they are headed, we offer design services, too. If budget is a concern, we offer a variety of options at many different price points.

Once you’ve chosen your glass project, we’ll take careful measurements, create your glass, and install the final product. We won’t consider a job done until you are satisfied with our work, from our initial conversation to the final piece of installation hardware.

If you need tempered glass in your next residential or commercial project, M&M Glass is here to help. Get in touch with our team to discuss your project today!