How to Cut Tempered Glass Easily?

By: Jan Hajek | Date Posted: March 1, 2018

If you’re a DIY-er who likes to do most stuff in the house, surely you’ve considered using tempered glass in one of your home projects. This kind of glass is not easy to work on, because it’s made to break if it is cut without the right process.

To make it simple, let’s concentrate on home projects that use this specific kind of glass to allow illumination and a variety of designs in home improvement.

Knowing how to DIY cut tempered​ glass can help in saving money because you don’t have to pay expert technicians to do this task.

It’s better to know how to do this and it’ll enable you to replace glass doors, sliding doors, and most of anything that needs this kind of glass. Using tempered glass because it durable and it’s safe when used in home designs.

Another benefit of knowing how to cut tempered glass is that later improvements in the home may allow us to use this material for constructing more complex projects with fewer mistakes!

I suppose now, we’ve got an idea of where this is going and you’re eager to learn more on this very helpful subject that easily teaches anybody, how to cut tempered​ glass without any risks.

What Do You Need to Cut Tempered​ Glass?

Before we start learning how to cut tempered​ glass, there are some items that one should be acquainted with before anything else.

Knowing how to use these items is important before you can cut tempered​ glass safely and efficiently without any injury or a few errors. Each item is important to learning how to cut tempered​ glass.

How to use each item before starting the process and what step in figures in?

1. Window washing fluid


Window washing fluid


This is a solution that can be bought anywhere, and this item is applied on the tempered​ glass to be used and will be spotless and clean, before any “heat treatment begins” on the material.

2. Craft furnace


Craft furnace


This is where the “Annealing” process is done. The oven has an adjustable temperature setting that is important in implementing the “heat treatment” of tempered​ glass. You have the option of getting different sizes so that you can “heat-treat” any size of tempered​ glass for your specific needs.

3. Glass cutter and Kerosene


Glass cutter


A glass cutter is a tool that’s used for etching lines and cutting glass. Kerosene is where you dip the glass​ cutter to make the cut neater.

4. T-square



A tool used for aligning and making sure that all sides are even when you cut the tempered​ glass.

5. 1/4-inch wooden dowel


1/4-inch wooden dowel

A dowel is used to separate the cuts made into the “annealed” glass. They come in “wooden”, “metal”, or “plastic” rod shapes that are important in one of the last stages.

6. Whetstone



It’s a stone that is fine-grained for sharpening or cutting tools. This is used in the last stages of the process of cutting tempered​ glass. This is basically what makes the tempered​ glass ready for its final application.

7. Eye and Hand protection


Eye and Hand protection

These are goggles worn over your eyes to avoid injury to them, just in case any accidents happen. Safety is important when working with glass; remember to wear gloves to protect your hands as well.

Process On How to Cut Tempered Glass Easily

Here is the meat of this DIY, the most effective way to cut tempered glass for any project that you need. In mastering the technique, you will have the confidence to do it yourself with ease.

Tempered glass cannot be cut without breaking into bits! You need to understand the process of ‘Annealing,’ which involves heating tempered glass to alter the internal structure and stress points.

Without “heat-treating” the glass it would be impossible to cut. In mastering the annealing process, you can learn to manipulate the shape of tempered​ glass by cutting or even re-tempering when you’re familiar with the process.

Step 1


       Process of cutting tempered glass

You need to make sure that the tempered​ glass for cutting is not too big or small for your immediate requirements.

Deciding on the final design you will work on will help a lot, and taking into consideration the annealing furnace’s size is an important consideration.

You need a glass cleaner or washing solution to ensure a clean surface. Do this in the initial stages of the ‘annealing’ technique.

Step 2

  Heating treatment of tempered​ glass easily


When the heating treatment begins, the end goal is the elimination of “stress points” in the tempered​ glass. In this stage, you must let the kiln reach an ‘annealing’ temperature of 900 degrees Fahrenheit or 1013-poise.

Soak the material at a ‘stable heating’ temperature in the furnace to make the glass less tempered, allowing you to cut it without it breaking apart.

Once you’ve determined the entire process, place the glass where it was heated and let it cool for 8 hours, or any duration you judge necessary throughout the entire process.

Step 3

  Cooling the tempered​ glass

The next stage is cooling the tempered​ glass, allowing changes for a slow and gradual drop in heat applied so the “stress points” will not show in the glass structure. As a marker, the suggested “strain point” temperature is “1014.5-poise”, from there cooling is gradual to eliminate the temperateness of the glass.

Leave the material inside the oven until the de-tempered glass has reached room temperature. Different kinds of glasses have differing cooling temperatures.

Step 4

  annealing treatment


Once you complete the annealing, you need safety goggles, a glass cutter, and kerosene. After the annealing treatment, you have de-tempered glass with no more stress points, so any cutting you do will not shatter it anymore.

Put a T-square over the area that you will begin cutting. A pro-tip is to dampen your glass cutter with kerosene, which will make a clean cut on the heated-treated glass. Use a glass cutter to make a straight line with a T-square to ensure the line is correct. Apply moderate pressure and run it over the line just once.

Step 5

  lines are etched on the glass

After you etch the lines on the glass, use ¼ inch wood dowels on the etched lines. If you don’t make the lines cleanly, the ridges won’t come apart evenly. Once you place the ​dowels​ and apply enough force to them, you will create a neat ridge.

Last thoughts on how to cut tempered​ glass

How was this DIY-er on “how to cut tempered​ glass”? Was it easy to follow and understand the text? Did it give you a clear idea of how to go about it and clarify some confusion about the entire process?

If it did, then you can understand the importance of how the de-tempering of glass and the items involved in the process go together in achieving the result. This will allow you to work on home projects yourself, which requires a technician and you save money.​

Did the information​ allow you to learn “how to cut tempered glass”, if it helped much then kindly share if you can. Keep in mind that initial attempts may not be successful, but following the tutorial and continue refining your ​technique further will produce better results in time.

If you are a DIY homeowner, check these articles too:

Lawn Stars: 5 Essential Landscaping Tools for Your Next DIY Project


How can you tell if the glass is tempered?

Tempered glass has smooth and even edges because of the extra processing it goes through. On the other hand, if the glass is not tempered, you will feel rough edges.

Is there any way to cut tempered glass?

You cannot cut tempered glass using the same methods as you would for ordinary glass. You will need to heat it to nearly 1,000 °F, then slowly cool it. This process, called annealing, effectively undoes the tempering process, weakening the glass to the point that you can cut it.

What household items can I use to cut tempered glass?

To cut tempered glass you will need window washing fluid`, a glass cutter, kerosene, T-square, 1/4-inch wooden dowel, whetstone, eye and hand protection, and most importantly a crafting furnace.

Thank you for reading!

Jan Hajek

I am an experienced writer. I write about home improvement topics such as construction, electrical work, plumbing, security and safety, interior design, exterior design, tools and woodworking, gardening, and garage organization. I love helping people improve their homes and make them more enjoyable places to live.

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