The Complete Guide to Drilling a Hole in Glass Using Diamond Drill Bits


A diamond drill bit is an essential tool in the manufacturing of diamond tools and other related materials. Drilling a hole in glass is not an easy undertaking. If not done correctly, you will end up shattering the glass and probably wounding yourself as well.


However, by being here, you have taken the first step towards doing it right. In this article, we will examine how to drill a hole in the glass without encountering any hassle. Which tool is most suitable for drilling; we will discuss how to prepare the drink.

Section 1 diamond drill bit – What Should You Know About Glass?

Why is it so hard to drill a hole in the glass? The answer is that glass is a brittle material. While it is hard and sometimes super-strong such that it can withstand tremendous impact, by its very nature, it is a brittle material.

You can create glass from several things, including a combination of sand, soda, and lime, among other things. Apart from having differing materials, the process of creation also differs. Regardless of the materials used or the method of the invention, most glass types remain brittle. And this renders drilling a hole in the glass without breaking it quite hard.

Section 2 diamond drill bit – Choosing the Right Tools for Drilling

With the right tools and technique, you can drill a hole in the glass without any hassle. Before you settle for a device, you need to determine which materials went into making the glass. You will also need to take into account the conditions within under you will be drilling the glass.

Picture of a drill bit
(Picture of a drill bit)

As mentioned, glass is a brittle material. Thus, you will require a sharp, hard bit to drill it. Generally, there are two types of drill bits suitable for use when looking to dig a glass hole. There is the tungsten carbide-tipped drill bit and the diamond-tipped drill bit.

Carbide-tipped drill bits are the most common drill bits. People use them for drilling non-tempered glass, ceramics, and tiles. Diamond drill bits are the alternative to carbide-tipped drill bits. They are much more challenging than carbide-tipped drill bits and, as such, can do a better job of drilling a hole in the glass. Diamond drill bits are even better for specialized glass drilling jobs such as drilling holes through windows and mirrors that pipes can pass through, among others.

A diamond drill bit is your best bet to drilling a hole through glass, especially if you are new.

By the way, it is not impossible to drill a hole in the glass with a regular drill bit. However, you will require a superpower to do so without breaking the glass. The alternative is hours upon hours of practice, droves of patience, and superb skill.

Apart from the diamond drill bit, you will also need the following materials:

  • Cardboard
  • Lubricant, oil, or water
  • A flat surface (on which you will place the glass)
  • Marker (for delineating the drill site)
  • Drill (cordless or corded)
  • Gloves
  • Coverall (or long-sleeved clothes)
  • Glass drill bit (preferably a diamond drill bit)
  • Painter’s tape
  • Safety glasses
  • Long pants
  • Cushion (optional)

Section 3 diamond drill bit – How to Drill a Hole in Glass

Once you have chosen your tool, whether a diamond drill bit or a carbide drill bit, you can drill the hole you want. The following will guide you through the process of preparing a hole in the glass.

Diamond drill bits
(Diamond drill bits)

3.1 Safety Measures You Should Take

So, you have a diamond drill bit for cutting through glass. The next thing is to get straight to work. Not so fast, though. Before you get down to using your new diamond tools, you should first ascertain your safety. Drilling a hole through glass could result in pieces of glass flying around, and you will undoubtedly want to protect yourself from harm. The last thing you want is to avoid drink from entering your eyes or piercing your skin.

To protect yourself when using your diamond tools, you will need the following:

  • Safety glasses
  • A thick pair of gloves
  • An overall (or long-sleeved clothes, at the very least)
  • Long trousers

3.2 Steps to Drilling a Hole in Glass

Once you have taken safety precautions, you can now get down to drilling. Following is a step-by-step guide on how to do that. Before you begin, attach the cardboard to the drill site on the glass with a painter’s tape. Your glass drill bit (preferably a diamond drill bit) will drill through this first, which will help it achieve a good grip beforehand.

  • Outline where you intend to drill through with a marker.
  • Attach your glass drill bit (start with the one that has a small width) to your drill.
  • Don your safety attire: gloves, coveralls, etc.
  • Place the glass on a flat surface for support (if you have a cushion, use it), and tape it down.
  • Power up your drill and start drilling. Slowly!
  • Discard the cardboard once you’ve drilled through it and into the glass.
  • Spray water, lubricant, or oil as you drill to prevent overheating.
  • Pause your drilling once you are almost through to the other side
  • Flip the glass and drill through the hole on the other side

NB: Drilling through the hole from one side can result in the glass shattering. On the other hand, completing the drilling via the other side minimizes this risk.

3.3 What You Need to Notice When Drilling a Hole in Glass

When you are drilling a hole in the glass, you must pay attention to where the glass is thinnest. Places such as this are the easiest to drill holes in glass. It helps to notice such sites and start from there if you are new to drilling a glass hole.

Section 4 diamond drill bit – How to Drill a Hole in Glass Without Breaking It

The following steps will help you drill a hole in the glass without breaking it.

4.1 Always start with a new drill bit:

You should know about diamond drill bits (and other glass drill bits) to get dull with use. As such, endeavor to use a new, fresh diamond drill bit whenever you want to drill glass. Using a flat bit is a recipe for failure, as shattering the glass will significantly increase.

4.2 Provide support for the glass at all times:

If you want to drill a hole in the mirror without breaking it, you must provide support for it. Before you embark on the drilling process, place it on either a sturdy surface or a cushion.

4.3 Control the speed of the operation:

Drilling a hole in glass requires buckets of patience. If you are the type that does things in a rush, then it is not for you. Patience and slow drilling will significantly increase the chance of successfully drilling the hole. Usually, the diamond drill bit (or any glass drill bit for that matter) you intend to use will give you an idea of the speed you should drill. In the absence of that, 400rpm is enough.

4.4 Start with a small hole size:

No matter the size of the hole you intend to drill, always start with a small one. Then, as you proceed with the drilling, widen the drill bit you are using until you finally achieve the size you want.

4.5 Ensure the Glass’s temperature is cold at all times:

One thing you can expect when drilling a hole in glass is for it to heat up. Another thing you can expect is for it to vibrate. When these happen, the glass you are drilling will shatter. For preventing this, it is advisable to shoot at a slow rpm and keep the drink cold. To do this – keep it cool – spray water on the drill site as often as possible. Alternatively, dab a small amount of lubricant or oil on the area as you drill.

4.6 Stay away from the glass’s edges:

When you are drilling a drink, it is advisable to put a distance of, at least, ¾ inches from its borders and the drill site. Anything more, and you will be risking the glass shattering. The reason is quite simple; drilling close to the glass’s edges means that it doesn’t have proper support. And without sufficient permission, while shooting, glass has a propensity to shatter.

4.7 File the hole upon completion of drilling:

Finally, endeavor to fill the hole you’ve drilled once you finish, especially if you will be threading a cable through it. It is not a secret that the jagged edges of the glass are sharp. And when you drill a hole through it, you will get these short, rough edges. To prevent these edges from slicing through whatever you are threading through the hole, file and smoothen the spot.

Section 5 diamond drill bit – How to Drill a Hole in a Glass Bottle

Glass bottle
(Glass bottle)

The principles of drilling a hole in glass are relatively similar across the board, albeit with minor differences and peculiarities. In glass bottles, the uniqueness lies in the type of drill press that you use. It is advisable to make use of a drill press when drilling a hole in glass bottles.

Glass bottles, by their very nature, are irregular. It is usually a result of their shape and design. The use of handheld drills is not advisable because of this. Drill presses, as opposed to handheld drills, free up at least one of your hands when you are drilling as you only need one hand to lower the diamond drill bit into the glass. As such, you can use the other hand to guide the bottle during the process.

Section 6 diamond drill bit – Can You Drill a Hole in Tempered Glass?

Tempered glass
(Tempered Glass)

Tempered Glass, also called toughened glass, is a type of glass that manufacturers cool rapidly during the manufacturing process, with the intention being to make it stronger. Tempered Glass is quite strong – about four times stronger than usual ordinary glass.

Apart from making glass very strong, the process of tempering also alters the glass’s property so that it is safer than regular glass. This property alteration allows the tempered glass to shatter into small, even pieces instead of standard glass, which breaks into big uneven pieces. The significance of this is that tempered glass is safer.

Because of this, it is impossible to drill a hole in tempered glass, whether through the use of diamond tools or standard drill tools. Any attempt to do so will result in grains of shattered glass.

Section 7 diamond drill bit – Can You Use the Dremel Tool to Cut glass?

If you have a Dremel tool and wonder whether you can use it to cut glass, the answer is, “Yes, you can!” However, it is not advisable to do so. Even Dremel, the company that manufactures these tools, advises against it.

If you do decide to cut glass with a Dremel tool, take necessary precautions.

You can use a Dremel tool to fashion a drinking glass, vase, or candle holder from a commonplace bottle.

Dremel tools are super-fast: Their RPMs range between 10,000 and 35,000. This fastness is the reason why they produce cuts of such superb quality. Without a steady hand to guide them. However, their results can be less than satisfactory.

Advantages of Dremel Tool

The significant advantage of working with Dremel tools is that they can produce very high-quality cuts. Another advantage is that you can use them for other functions apart from drilling, such as polishing and grinding.

The Working Method of Dremel Tools

Dremel tools rely on the concept of high speed to serve the functions they perform. It is in opposition to the high torque concept that typical, simple drill tools use.


Cutting a hole through glass is easy, but only if you know how to go about it. The most important thing to know is that a hard drill bit (such as a diamond drill bit) essential. Just as important is being patient; cutting slowly; and sprinkling water, oil, or lubricant to prevent overheating.

At NCCuttingtools, we sell genuine diamond drill bits. We also possess the expertise and experience to guide you through the process of drilling a hole in the glass. Contact us today to start.

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