How To Drill A Hole In Tempered Glass

How To Drill A Hole In Tempered Glass? – Can It Be Done?

Tempered glass is strong and durable but is not meant to be tampered with and manipulated after the tempered process.

You also need to be highly skilled and in an industrial setting. Cutting and drilling tempered glass are classed as impossible, so consider yourself lucky if you manage to do it.

If you do cut the glass, know that the glass will be weak now and will not be able to withstand heavyweight or moving around without shattering.

The truth is, prepare the glass how you want and drill where you want before it is tempered; that is really the only option you have when it comes to drilling holes in tempered glass.

How To Drill A Hole In Tempered Glass?

Put the glass into a craft oven or kiln, which will heat the glass to 900 degrees Fahrenheit (482 degrees Celsius). The glass then goes through a cooling process. This simply means to remove the temper so the glass is back to normal glass, which then can be drilled. Tempered glass cannot actually be drilled on as standard glass can.

What Exactly Is Tempered Glass?

Tempered glass is also called safety glass and is used often in everyday life. Tempered glass is just standard glass that goes through a thermal process that will increase durability and strength.

After the tempering process, the glass surface goes into compression while there is a pressure state located in the glass.

This is how they get the tempered glass to smash into little chunks that aren’t sharp, unlike normal glass that is sharp and jagged when broken.

This is done to make the glass safer when it breaks. This is why tempered glass is often found in many public areas, car windows, and households.

Tempered glass is favored for common applications because of the safety and strength levels it has. Tempered glass is even used in bulletproof glass.

There are both upsides and downsides to tempered glass. The biggest downfall is that tempered glass cannot be drilled or cut after it has been tempered.

If you want cuts or holes in the glass, it must be done before the tempering process has started.

How To Check If The Glass Is Tempered!

The simple way to check if the glass is tempered is to break it. If it breaks into small blunt pieces, then it is tempered glass.

Unfortunately, if this is a window or a table, you are not going to smash the glass, so you will need to use some of the other ways to check if the glass is tempered.

Check The Glass For Watermarks

You can check the glass for a watermark that is often located in the corner of the glass and will contain the safety approval markings and the manufacturer’s details.

Look carefully and check each of the corners because it can be difficult to see if it is between the different layers of glass, or it could have faded if the glass is old.  

Inspect The Edges

If the glass has edges that are uncovered, you have to look over them to see if you can spot any chips.

If the edges of the glass are smooth, then the glass is most likely tempered. If the edges are rough, it is normal, standard glass.

Are There Any Imperfections?

Due to the process where the glass is heated, tempered glass can sometimes contain bending, dimples, and warping.

You need to look over the glass and see if you can see one of those defects. You can also look for tong impressions which are a tool used to remove the glass from the kiln. If you find some, then congratulations it’s tempered glass.

Grab Yourself Some Polarized Sunglasses

Grab some polarized sunglasses and add some sunlight, and you can see whether the glass is in fact tempered. There will be a pattern of lines that go into a grid of the surface of the glass.

You can also take a photo of the glass via a filter that polarises images. These can be brought online.

Score A Line

The important thing with the type of testing is the fact it should only be used on glass you are cutting anyway.

Don’t do this on new glass or glass you certainly don’t want to shatter. If you want to cut glass, it is important to know you can only drill and cut standard glass.

You can check the type of glass you have but using a tool called a window cutting tool that can be brought to your local hardware store. Draw a line with the tool across the glass, and if you get a bumpy, uneven line, you most likely have tempered glass.

The standard annealed glass will have a clean line when it has been scored. If you still cannot determine the type of glass you have once you have scored it try again in another area and then compare the two marks.

If you still cannot make a determination and if the piece of glass is transportable, you can take it to a professional glass dealer who will be able to tell you which type of glass you have right away.

The Deal Is Tempered Glass Cannot Be Drilled

It should be quite clear now that tempered glass cannot be drilled. If you wish to have a hole in your tempered glass, the only way this can be done is before the glass is tempered when it is still in the annealed state.

You can try to manipulate tempered glass but be careful, and there are no guarantees that it won’t break. Even trying this can weaken the glass even if it doesn’t break, so be aware of that.

Is It Possible To Drill Annealed Glass?

Annealed glass happens to be basic glass that you might see on your bathroom mirror. Annealed glass is a heat treated glass that needs to be cooled down extra slow to allow any inner stresses to be released.

Annealed glass is a lot cheaper than tempered glass. Now for the question of can you drill annealed glass, you certainly can.

While this is possible, you need the right procedure to follow and the right tools.

Cutting tempered glass can only be done by transferring it back into the annealed glass state. This is simply not worth the effort or the time.

Difference Between Standard Glass And Tempered Glass

Tempered glass or safety glass is durable and strong due to it being prepared by a tempering process which is done by taking standard glass and heating and cooling it in a special way.

Ordinary glass is 5 times weaker than tempered glass that has internal stressors. 

Tempered glass is safer due to the internal stresses that hold the glass in place, which means when it shatters, you won’t have harmful shards of glass.

Did you know that glass is actually sand? Ordinary sand can be heated until it turns into a liquid which is mostly made up of the natural compound silicon dioxide.

It is basically in between liquid form and solid with some molecular randomness as the liquid and the crystalline order of a solid.

Why Can’t You Drill A Hole In Tempered Glass?

Tempered glass is made to break into granular pieces if it happens to break. It is near impossible to drill a hole into the safety glass due to the fact it is designed to be safety glass.

The tempered glass is made so that the pressure is distributed evenly around the piece of glass.

It is at this point that if you have a break; you will see web-like cracks throughout the tempered screen protector; this isn’t just limited to where the damage was done.

Tempered glass is very durable, which is why it is a common choice for everyday items like tables, glass doors, and microwavable items.

Tempered glass uses a chemical and thermal process which gives it strength. The glass is compacted in the center and compressed on the outside, so when the glass breaks, it shatters into small pieces to minimize the damage.

People say it is not possible to drill into tempered glass, even for a tiny hole, as it will shatter right as the drill touches the tempered glass.

For a hole to be successful, you would need to do it before the process of tempering has started.

If you have a very thin layer of tempered glass, such as what you find on a mobile phone screen, it might be easy to drill into in an industrial setting, but thicker types and larger pieces are not able to be cut successfully once the tempering process has started.

Can You Cut Into Tempered Glass?

Most people will tell you that just like drilling, you cannot cut tempered glass. There are some cases where people have used a diamond blade or porcelain tile cutter, which, on the off chance it worked, but many others have failed to cut tempered glass.

Many will tell you that once the glass has been tempered, there is no way you can manipulate it and work on it, such as cutting and drilling.

How Tempered Glass Breaks

It is the curing process that makes tempered glass brittle, where you will see the whole panel of glass completely shattering into tiny pieces instead of just breaking right at the point of impact.

Due to the fact that tempered glass is quite strong, it doesn’t happen to break immediately every time but will crack and then eventually break, especially when under pressure.

Is It Possible to Laser Engrave Tempered Glass?

Yes, you can. Tempered glass can be engraved, but there is a problem with the outcome of that, due to tempered glass already going through a high heat process that makes the exterior stronger.

This also heightens the tension within the additional inside layers of the glass, meaning they are now vulnerable.

When the laser cuts into the tempered glass quite often, it will completely shatter. If it happens to not break, it will still lose its primary purpose due to being weakened.

If you have, say a tempered glass table or chopping board that has been engraved, it may shatter when it is exposed to a hot temperature like a hot cup of coffee.

Experts say that it is best to be engraved before the tempering process takes place. This will help to compress the outer surface and keep the shape.

Read about how to clean tempered glass here.


By now i think we can say you understand that you cannot in any way drill a hole or cut into tempered glass without it shattering.

There is no way around doing this; it just isn’t possible. If you read that people have done it successfully, most likely, they confused normal glass thinking it was tempered.

People have attempted to grind a hole into tempered glass, but many have failed, and it will cause the tempering method to lose integrity.

By all means, you can try and see if it works for you, but you should only do this on glass you don’t want anymore.

Ensure when you attempt this that you put safety glasses and other protective gear on to avoid glass flying into your eyes or slicing your hands on the shattered or broken glass.

A mask is also important so you don’t end up breathing in the glass dust, which can be fatal.

Frequently Asked Questions About How To Drill A Hole In Tempered Glass

Is All Tempered Glass The Same?

When it comes to drilling or cutting, the same rules apply it cannot be done. Whether it is tempered glass shower screens, aquariums, and even windows, you cannot drill or cut it without shattering it.

Is There Any Way To Cut Tempered Glass?

You might have some luck cutting the tempered glass with a laser cutter and other sophisticated tools, but this isn’t for sure, and these are not the tools that the general public can gain access to.

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