How to Drill into Granite Rock?

Granite is one of the familiar and common intrusive igneous rocks that is also used in construction as an interior or exterior component. However, for its hardness, longevity, and unique appearance in home decoration people use this rock a lot. Mostly, it’s used in countertops, or as floor tiles. So, many of us need to drill granite often. Whatever, drilling granite isn’t easy to drill on other surfaces like concrete or drywall. So, how to drill into granite rock?

When you aren’t professional at drilling, you may be concerned if you need to make a hole in a granite slab. The reason is that it’s an expensive object than a concrete slab or ceramic tiles. Hopefully, you can do it with your drill machine though you need some extra materials for the task and also need to know some strategy. Let’s know those tips and follow them. Your fear will turn into fun.   

The process of drilling a granite rock

The process of drilling a granite rock

Almost all over the world and especially in mountain ranges, granite’s found on surfaces mostly in large plutons. What we know about granite is that it’s formed from coarse-grained quartz, plagioclase, and alkali feldspar. For its formation, it’s quite hard. To drill this hard object, I’m noting down some steps to follow. The steps are:

Selecting a method

In fact, there are two ways to drill any granite slab. They are-

  • Dry method and 
  • Wet method.

In the dry drilling method, you don’t need to soak the bit and granite slab in the water. Some manufacturers are making such types of drills that can drill without water attachment. You can drill fast in dry coring but keep in mind that there are risks of cracking or damaging. So, be careful and pick a good quality drill.

On the other hand, you need to use water for the bit and slab in wet coring. In the whole drilling process, you need to soak these several times. To me and other experts, it’s the best method as the chances of damage are less and you will get a flawless hole as well as less dust. Although it takes more time than dry coring, perfection is also important for granite. 

Selecting the required tools 

The second step is arranging all the tools. If you want to drill granite, you must need the things below:

  • a drill machine,
  • a drill bit,
  • a bowl of water (not necessary for dry coring),
  • a vacuum (compulsory for dry coring),
  • a diamond polishing pad,

Besides, we need to know some more information about the objects to choose them correctly. Here, I’m describing the details of these.

Pick the drill machine:

According to MOH’s Hardness scale table, granite’s rating position is 7 which means it’s harder than concrete or even steel blades. This is why you need a high-medium strength drill machine. In markets, different types of drill machines are available but you should know a random drill can’t be appropriate enough to hit smoothly in granite. So, it’s better if you take a rotary hammer drill. If the whole size needs to be big enough then the rotary hammer drill is quite perfect.

On the other hand, if the hole needs up to ⅞”, simply you can use a cordless drill with 12v to 18v. Eventually, such drills take time but finish the job anyhow.

Find a drill bit 

Generally, diamond core drill bits are mostly used for granite drilling but carbide-tipped bits are also effective. Different sizes of drill bits are available in both types. The sizes are-

½”, ¼”, ⅛”, ⅜”, 3/16”, and 5/16”. 

You may have heard that the masonry drill bits aren’t for hard rocks such as granite. Hopefully, some masonry drill bit sets which come with rock carbide tips are able to drill even in granite recently. Whatever, you can try one of these three types. 


Due to heavy rotation, the bits often get warm. So, experts advise soaking the drill for a while drilling. It makes the bit cool and also lubricates it. After that, it prevents dust too.


As you know before that in dry coring, dust is a problem. So, you must have a vacuum there.

In addition to these, you can use a diamond polishing pad for a polished surface, granite scrap, and a clamp for drilling from top to down.  

Ensure the safety

Additional objects for safety you should have. These are- 

  • goggles or face shield,
  • ear pads, 
  • dust protective mask,
  • full foot covering shoes.

As granite dust can easily enter the eyes and nose and cause serious hazards from eyesight problems or catarrh and this is why a goggle and a mask are most important to be safe. Thereafter, avoid open-toed shoes or sandals and loose-fitting clothes. Also, it’s better to use ear pads if the drill makes extreme sounds.

Drill the hole

When all are set perfectly, you can go for drilling. Follow the steps:

The facts to remember when drilling

The upgrade drills make drilling so easy and interesting. Nowadays we often drill holes on any surface as per our requirements. However, at first glance, this seems like a simple matter, but some simple mistakes can cause irreparable suffering. So, the mistakes that are usually made and should be avoided are mentioned below:

  • Fix the drill chunk tightly.
  • Like loose clothing, also avoid jewelry.
  • It’s normal to put some pressure on the drill but remember there can happen an accident if you put a lot of pressure.
  • If co-incidentally water spills on the drill, instantly turn it off.
  • Never hold the drill by its cable.

FAQ on How to drill into granite rock?

Can you drill on granite with your regular drill?

Yes, you can drill with the regular drill but it consumes more time than a rotary hammer drill. Although you must need a diamond core drill bit or carbide-tipped bit.

Should I use an anchor in granite?

Actually, anchors work perfectly on bricks, boards, or concrete. But such tough surfaces like granite which are natural don’t go thoroughly with an anchor. Nevertheless, if you prefer a screw with an anchor, you can use plow anchors.

What types of screws are good for granite?

Wood screws and lag bolts are suitable screws for granite. However, lag bolts are more durable and reliable because wood screws can be damaged by water contact.

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Samuel H. Murphy is DIY expert and Interior Designer. He is also a part time content writer of Capische. He lives in Warren city, Michigan. He test tools like drill, saw, sander, air compressor etc and helps readers to find out the best tools.

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