How to Drill a Hole in Tempered Glass?

Because they shatter upon the impact, drilling is not easy when it comes to tempered glass. Large pieces of glass have more chances to inflict an injury than shattered glass. That is why tempered glass is often used in public spaces, cars, shower doors, and tables.

How to drill a hole in tempered glass? It is not an easy question to answer. For a DIY enthusiast, it is almost impossible to drill a hole in tempered glass with a drill (although I have explained one method that is difficult to carry out successfully but is not impossible). Although the industrial-grade laser can cut a hole through the tempered glass but at home, all you can do is drill only a small amount on the surface (Edgework), but going deep will shatter the glass.

From a safety point of view, tempered glass is intentionally designed to shatter when it breaks. As mentioned above, this makes drilling into it quite difficult to nearly impossible. But before we discuss few tricks to work our way down, let us briefly know what is tempered glass and why it breaks?

Why Does Tempered Glass Shatter?

Tempered glass is also called safety glass and is actually a thermally treated annealed glass. The surface layer of glass is compressed to keep tension in the middle layers of the glass. This tension is the reason for the shatter when it breaks. This property is useful but sometimes can also be a headache. Below I will shortly discuss the pros and cons of using tempered glass.

tampered glass shattering

Pros of Using Tempered Glass

  • Tempered glass has greater strength; this is because it is thermally treated.
  • It has a low danger of causing injury due to its safety profile.
  • It has a high heat resistance rating.
  • It’s crystal clear and is highly versatile.
  • Due to its high strength, it is also scratch-resistant.

Cons of Using Tempered Glass

  • Although rare, it can sometimes break spontaneously, even without an external force.
  • Modifications are nearly impossible.
  • Drilling into it isn’t easy.
  • Not ideal for a DIY enthusiast.

Methods to Drill a Hole in Tempered Glass?

Internet is flooded with a single statement that it’s nearly impossible to drill a hole in tempered glass. But I have a different point of view. I think that: at least theoretically it is possible to drill a hole in tempered glass. I will be discussing them briefly below.

1. Using Laser

Laser cutting machines are bulky and highly advanced systems that can cut tempered glass. They need professional workplace and staff. CO2 laser system is such an example. The laser upon impact with glass produces high energy which cuts through the glass.

Laser cutting tempered glass

The heat prevents the glass from shattering because the adjacent layers of glass are transformed into toughened glass.

2. High-Pressure Water Jet

waterjet drilling hole in tempered glass

This is an excellent and optimal method to cut a hole in a tempered glass but is limited to the glass thickness of no more than 350mm. This is a non-thermal method, so avoid building up heat-affected zones and molecular vibrations. This also has the advantage of a smooth finish. The pressure required is 6200 Bars which translates to 6118.924 ATMs. The feeding speed is 15 meters.

The one disadvantage of this method is high cost of machine. This is only available at professional workshops.

3. Using a Cordless Drill and Epoxy

This is the only DIY method used to drill (it’s actually grinding) a hole through the tempered glass, but the success rates are meager and require repeated trials. You need the following items to drill into a tempered glass:

  1. A Cordless drill
  2. Diamond drill bits.
  3. Epoxy
  4. Rubber pad
  5. Water or a coolant.


I will describe the procedure briefly to make your DIY project as easy as possible for you. Follow these steps for best results,

Step 1: Safety is of prime importance when it comes to drilling. Protective gloves and goggles should always be used prior to engaging in such projects.

Step 2: Position the glass appropriately onto the table using a rubber pad placed under the glass. This is because the rubber pad dampens the vibrations.

Step 3: Apply epoxy around the area that is being drilled. This supports the glass layers by providing extra support. I personally recommend J-B Weld 8281 Epoxy because of its high strength and cost-effectiveness. The procedure is simple. Mix the two epoxies in 1:1 and then apply them around the area that is being drilled. Wait for some time ( it takes 4-6 hours to set and 15-24 hours to cure).

Step 4: Next, mount an appropriate-sized diamond drill bit. It is recommended to start from a small-sized bit and then jump to the intended size.

Step 5: Make a pond for coolant or water out of flour-putty around the area that is being drilled

Step 6: Now, drill under low rpm and avoid hammering at any cost; moreover, refrain from applying any pressure.

Step 7: Take your time and wait intermittently to avoid heat buildup.

Step 8: Once you drill a hole through tempered glass, don’t forget to remove the epoxy (a towel soaked in acetone will help).

How can you tell if glass is tempered?

It can be quite difficult from a superficial view to know if the glass is tempered, but few tricks will help you identify it.
1. They have smooth edges. This is done because once the glass is tempered, it’s nearly impossible to work with it.
2. Watermarks are present on tempered glass for safety approvals and contain information about the manufacturer. This is a good indicator for tampering.
3. Look for heat stress signs like dimples and imperfections. They are a good clue to know about tampering.
4. If the glass is tempered, putting on polarized glasses and seeing the glass under the sun creates the illusion of parallel lines.

How do you make a hole in a tempered glass phone?

You can only drill a hole in a tempered glass phone before it is being tempered. Phone glass is very thin and intentionally designed so that it has to shatter when it breaks. Therefore there is no shortcut to drill a hole in a tempered glass phone.

Do you need a special drill bit for glass?

Yes! for a nice and easy project and a nice hole, you need to use specialized drill bits intended to drill into glass. They consist of
1. Carbide tipped drill bits.
1. Diamond drill bits (better than former).