Can I Drill a Hole In Granite? - Our Best Guide
Granite is a very dense and strong material, often used on kitchen countertops due to its variety of patterns and stain-free finish.
Although granite is beautiful for our homes, drilling it can be a big task due to how hard and brittle it is, also granite is often installed as a single slab, so one wrong move and you could potentially crack the whole thing.
It is very possible however to drill a hole in granite with the right tools on your hands such as a diamond drill bit, some scrap stone and wood, you should always ensure that you are using the correct equipment too and wear safety gear when attempting this task.
We have put together an extensive guide below all about drilling granite so as you can drill your countertop or granite surface properly without ruining the whole slab.
What Is Granite?
Granite is a type of rock that is very hard and wear-resistant, it comes in at 6 or 7 ratings on the Moh hardness scale too and is mainly made up of quartz and feldspar.
This material is one of the most natural forms of materials you can use in a building and is mainly used for countertops due to the fact it can't be stained or scratched.
Why Is Granite Difficult To Drill?
This rock in particular is very hard to drill due to the fact it is quite brittle at the edges, meaning it will take double the time to drill in comparison to other materials.
Drilling through granite requires the right drill bit too and some other pieces of equipment to keep things safe and stable while avoiding cracking the granite.
Which Drill Bit Should I Use For Drilling Granite?
To drill through granite you will need a special diamond drill bit for the job, avoid using a masonry drill bit as this would most likely get stuck in the granite.
We have listed out some important factors to consider in your drill bit for granite below.
- Bit size - You will often be faced with picking a size between 1-50mm when choosing your bit size for drilling granite, you should choose the size according to how big or small you want the hole to be.
- Bit shape - Arrowheads or circular tips are the most popular kind of bit shapes, both can be chosen according to the hole you want to make.
- Bit material - For granite drilling, we suggest only using a diamond drill bit, however, you may also be able to use carbide or diamond coated bits instead, never use the wrong drill bit as this can stick and crack the granite.
How To Drill Granite (Our Step By Step Guide)
Now we know some more about granite and how to pick the best drill bit for the job, let's get into how to drill through granite.
You will need some specific tools and we also suggest clearing the workspace away from pets or animals during this process so as you can avoid any accidents, always wear safety equipment such as goggles too.
- Diamond drill bit.
- Your drill.
- Scrap stone and wood.
Step One - Choose The Size Of The Hole & Mark The Area
First off, you should figure out how big you need to drill the hole and use the appropriate sized drill bit in correspondence. Mark the drilling area with a sharpie clearly, you can also clamp some wood and mark the wood to avoid chances of cracking the granite, put a piece of scrap stone over the drilling area too and clamp all in place.
Step Two - Install Your Diamond Drill Bit Securely
Now attach the chosen size drill bit to your drill, we recommend using a diamond core drill bit for this job as it will be able to handle the granite with ease. Ensure there are no loose attachments on the drill as well to avoid breaking the granite.
Step Three - Start The Drilling!
Start drilling over the marked area with steady and light pressure, you can put some lubrication on tip of the drill to reduce the temperature build-up too, this will also make the drilling easier. Never force the drill into the granite and let it gain speed gradually. Some people recommend drilling for 10 seconds on then 10 seconds off to give the drill bit a chance to cool.
If drilling multiple holes, let the bit cool down before moving on to the next one!
Step Four - Clean Up
Stop drilling the granite until you reach the scrap stone. After you have made your hole, clean up the excess lubricant straight away so as it does not sink into the pores of the granite. You can always use water instead of lubricant just in case to avoid this.
Safety Tips & Tricks For Drilling Granite
- Use water to prevent dust - When drilling granite, there will likely be a lot of dust build-up on top as you start drilling, spray water over the granite to prevent this so as you don't inhale too much and spread it around the room.
- Lubricate the drill bit - Use water, lubricant or oil to reduce the dust from the granite and keep the temperature down on the drill bit.
- Go steady and slow - Never apply too much pressure on the drill while you are dealing with granite, doing so could increase the chances of damaging the drill or cracking the granite.
- Wear safety equipment - Goggles are a must when drilling granite, you should also wear a mask and potentially earplugs, as you will likely be drilling for a long time.
- Use a bottle cap - Find a bottle cap with some depth and place it upright over where you want to drill so as it can act as a cup. Use some putty to hold it in place as you will drill through the centre, this will also stop the lubricant from spilling on to the granite around the sides.
Frequently Asked Questions About Drilling Granite
How easy is it for granite to crack?
Granite is very heavy-duty but will crack like other durable materials when it's hit with enough pressure due to it being quite brittle. This is why you should always use the correct drill bit and go slow.
What is a diamond core drill bit?
The teeth on a diamond core drill bit feature diamonds, these diamonds are very hard and allow you to drill through materials like granite with ease, these bits are a step up from carbide tipped drill bits.
These core drill bits also act as a plug when they are being drilled into the material, so effectively draw a circle out of the granite.
How easy is it for a drill bit to overheat?
A drill bit can overheat easily when used at too high of a speed for too long on heavy-duty material. This is why you should use lubricant and take breaks when drilling. When your bit overheats this will not only ruin the bit but possibly the material too, always stop drilling if you smell any burning.
Should you use a hammer drill for drilling granite?
No, some people recommend a hammer drill for tough material, but granite is not one of them, hammer drills are too aggressive for this kind of countertop and can potentially crack the material.
Overall, drilling granite is a slow and steady process that should not be rushed, always use a diamond core drill bit and use the necessary accessories such as scrap wood and stone to avoid cracking the granite. Also, apply lubricant when dealing with a tough material like this to stop the drill bit from overheating and make sure to wear goggles and a mask to avoid breathing in the dust created.
We only recommend drilling granite if there is no alternative, as this rock is very expensive and not easy to make holes in, so if your hole is for electricity or plumbing, try to see if there is a way around it, and never drill more than 1-inch to the wall, as this can increase the chances of the granite cracking.