How to Drill a Hole in Glass
Be boring—in a good way! Follow this guide to take your glass- and mirror-centric DIY crafting projects to the next level.
You’re a crafty DIYer who’d love to create a lamp from an empty wine bottle or hook that mirror through a hole, but the thought of drilling through glass or other such fragile material stops you cold. With the correct drill bit and proper technique, it’s easy to learn how to cut a hole in glass and take on crafting projects you haven’t yet tried—that is, as long as you don’t attempt to bore through tempered or “safety” glass (identifiable by markings at the corner of the pane), which will shatter upon applying mechanical force.
Choosing the Best Drill Bit for Glass
Bits suitable for boring glass have spear-shaped carbide or diamond tips. These drill bits have a spear shape that’s sharp enough to safely drill into glass without damaging it. Carbide- and diamond-tipped bits are much sharper than masonry and other types of drill bits, which will break or chip glass instead of boring a precise hole.
Available at most hardware stores, glass-boring bits come in various sizes. It’s a good idea to buy a small glass drill bit (either a 1/8-inch or 3/32-inch) for making pilot holes, and larger bits to suit the diameter of the finished opening you want to make.
When working with glass, it’s important to follow safety precautions carefully. Always wear goggles to protect your eyes from airborne glass shards. A dust mask will prevent you from breathing in glass and dust particles. Finally, safety gloves can help you avoid cutting yourself while working with glass or mirrors. cuts.
As to drilling technique, be sure to maintain low speed and moderate pressure. If this is the first time you are drilling a hole into glass, we recommend first practicing the technique on a spare piece of glass. Keep your drill rpm below 400. If you drill too quickly, it will generate heat that damages your drill bit.
The following steps will walk you through how to drill a hole in glass without breaking it.
STEP 1: Mark the drill site.
Make an “X” with two pieces of painter’s or masking tape at the drill site. In the center of the “X,” use a felt-tip marker to indicate the precise spot where the hole will be. The tape will give your bit some traction and keep it from wandering on the otherwise slippery glass surface.
STEP 2: Secure the glass for drilling.
Secure the glass object you’re working with. Lay panes of glass on a pad or other cushioning material. If you’re drilling into a glass bottle and find it easier to work on the object at a slight angle—say, 45 degrees—place the bottle on its side, with the marked drill site facing up, lift by the neck to the angle that feels comfortable, and hold the neck to keep it from moving while you drill with the other hand.
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STEP 3: Choose your starting drill bit.
Choose a drill bit for cutting glass that’s smaller than the hole you’ll end up drilling. Either a 1/8-inch or 3/32-inch carbide- or diamond-tipped bit is a good choice to create a dimple or pilot hole in your glass. Insert your bit into the chuck of a variable-speed drill.
Don your protective gloves, goggles, and dust mask, and you’re ready to get started. Hold the drill at a right angle (90 degrees) to the glass surface. Begin drilling at a low speed—below 400 rpm—to carve the pilot hole. Remove the tape when that’s done.
STEP 4: Size up your drill bit as needed.
Replace the starter bit with a larger one if your project calls for a wider hole. Continue drilling at about 400 rpm, and apply light pressure on the drill, so you won’t crack the glass. High-speed drilling causes overheating and glass-powder buildup at the drill site; it can also ruin the bit.
STEP 5: File the edges of the exit hole.
When you drill glass, the entry hole will typically be clean and smooth, but the edges of the exit hole might be sharp. Gently file down any chips or jaggedness with a 600-grit diamond file that fits into the hole. Rinse to remove all residual dust.
There are plenty of projects you can start once you learn how to drill a hole in glass. The key to creating a smooth, clean hole through the glass is by using a low rpm, moderate and consistent pressure, and always starting with a small pilot hole.
For novice DIYers who are not sure to achieve 400 rpm on a variable speed drill, the speed is easy to approximate: If your drill reaches 1500 rpm when you fully depress the trigger, holding the trigger halfway down brings the rpm to about 750. Squeezing the trigger half as much as that brings you down to approximately 375 rpm. That’s in the right zone for drilling a hole in glass.
As with any new skill, practice is key. Before you dive into a project, take some time practicing drilling holes in glass that is similar to what you will be using. This exercise helps you get comfortable and confident so you can get to work fulfilling your most ambitious crafting projects.
FAQs About Cutting Holes in Glass
Even those who are DIY beginners can drill a hole in glass by following the steps in this guide. Drilling glass doesn’t have to be an intimidating project, provided you follow our instructions and equip yourself with the tools and knowledge to do it safely. To provide you with ample know-how, here are some frequently asked questions and answers about how to drill a hole in glass.
Q. What kind of drill do you use for glass?
A variable speed power drill is the tool you need for drilling through glass; however, you’ll need a spear-shaped carbide- or diamond-tipped drill bit to get the job done. When in use, keep the drill at or below 400 rpm, as drilling into glass too quickly can damage the drill bit.
Q. Can you drill glass with a masonry bit?
Masonry bits are not as sharp as a diamond-tipped drill bit, so they won’t do the job of drilling a hole through glass. If you attempt to cut a hole in glass using a masonry drill bit, you will likely break or chip the glass. Using the right drill bit for the job makes cutting a hole in glass safer and easier.
Q. How do you make a hole in a glass window?
Making a hole in a glass window is delicate work if you are not removing the glass from the window casing. In this instance, hiring a glazier (a glass and window professional) may be your best bet. They use special glass-cutting tools to score the glass surface and cleanly pop out a hole.
Q. How do you drill a big hole in glass?
Drilling in glass uses a system of starting small and expanding gradually. Our instructions above explain how to create a small pilot, or starter, hole. Once you’ve created this starting point, you can increase the drill-bit size. Additionally, for drilling large holes in glass, a diamond-coated hollow drill bit cuts a broader diameter.
Q. Is it possible to make a hole in tempered glass?
We do not recommend that you attempt to drill a hole through tempered glass. This type of glass is designed to shatter on impact, which becomes very dangerous—especially if you are not wearing the recommended personal protective equipment. Tempered glass has smooth edges and small imperfections on the glass surface, and authentic tempered glass will be stamped with an identifier.