6 Tips for Choosing a Granite Drill Bit for Your Project

The granite drill bit is one of the indispensable tools in the diamond manufacturing industry. Also, if you specialize in drilling granite, one crucial aspect your drilling you can’t overlook is your choice of a granite drill bit. In this same vein, this article will be unravelling some vital tips as regards selecting your bit or bits for drilling granite.

These tips span across the different types of granite as regards levels, the two significant types of drilling, the long-term and speed factor, and the manufacturers you should look to for quality drill bits.

Different granite slabs
Figure 1 – Different granite slabs

1.Understand that there are different types of granite

We won’t be concerning ourselves with the colours as we will be analyzing the different grades of granites. Granites come in three categories –

• Low-Grade Granite 

Level 1: This is a commercial grade or builder’s grade granite. This type of granite is usually thinner, about 3/8 inch. Builders use it for remodelling and building apartments as it features a simple design. In this regard, you can conveniently use an electroplated (nickel bonded) diamond core drill as most of the works you will be doing will involve simple drilling. Plus, the granite is usually thin, which allows you to drill it seamlessly.

• Mid-Grade Granite 

Level 2: The mid-grade granite is a more expensive material than level 1. Plus, you can only import it from Brazil or India. It comes with a ¾ inch thickness. Due to the costly nature of this granite grade, we advise that you use a sintered (metal bonded) diamond core drill as you may be looking to have a nice finish. The sintered (metal-bonded) diamond core drill functions well in this regard.

• Top-Grade Granite 

Level 3+: This level if granite has more than three levels hence the “+” sign. They usually go up to seven levels if you’re looking to use them as countertops. The grade 3+ granite features a more exquisite design and colour. You can also cut them into ¾ inch slabs. Plus, interior builders use them to design Aqua kitchen and numerous bath designs. As similar to the level 2 grade, a sintered (metal-bonded) diamond core drill will equally play a significant role here, why? Well, it’s because the sintered diamond core drill gives an excellent finish with minimal loss of material. The Level 3+ granite is a high-priced material in the granite market, and as such, you can afford a maximum waste of it.

Knowing the grade

level of granite that you’re dealing with helps you to select a compatible granite core drill bit. You should also understand that the surfaces of these granite levels differ in smoothness. The Level 3+ comes with a more smoothened surface.

2. Never use an oversized core bit.

It isn’t just enough to select a diamond core drill for your granite project; you should also be wary of the hole size you’re looking to drill. Different projects feature different hole sizes, and this should influence your drill bit selection. Choosing an oversized drill bit can adversely affect your project, and we suppose you don’t want that. In this same vein, you should also check the specifications of the granite drill bit you’re looking to purchase, as this will give you an idea of the holes sizes the drill can make.

A heavy-duty drill bit
Figure 2 – A heavy-duty drill bit

3. There are two different types of granite drilling.

You can drill granite slabs using two primary methods. These two significant methods are dry coring and wet coring. Both systems come with their distinct advantages and disadvantages, and we will be discussing them –

Drilling through a granite rock
Figure 3 – Drilling through a granite rock

Dry coring 

Dry coring is when you drill a hole without the use of water in the drilling process. It is faster; however, it poses a threat to the bit as the drill might generate enough heat and cause it to melt. It also jeopardizes the granite drilling project as the surface of the granite slab might crack from too much friction. You can use this drilling process to drill holes in granite, granite countertops, and tiles.

• Wet coring

In wet coring, you use water in the drilling process. Water keeps the temperature of the granite surface and your granite core drill bit chilly, and invariably lessens the risk of any damage. This drilling method takes more time, and you will have to take care of a messy workspace. However, you get to safeguard your tool as well as your granite material.
In this regard, endeavour to go for diamond core drills that come with coolants or ensure that your drill bit is water-friendly.

4. Drill bits are best used only for granite drilling projects.

If you happen to be a granite drilling specialist, then you will direly need a granite drill bit that can serve you for long. There are several drill bits in the market space. However, we advise that you purchase diamond core drill bits as they tend to be the most durable core bits out there. Plus, diamond happens to be the most challenging material on earth. Furthermore, you need a drill bit that can match the energy coming from your RPM; a less-powerful drill bit might not do the job.

Drilling a granite rock with a metal core drill bit
Figure 4 – Drilling a granite rock with a metal core drill bit

For your granite drill bit to last, we advise that you use it for your granite drilling projects alone as using it to drill other materials might wear it out faster, and it may not wear evenly. What does this mean? Using one drill bit to train different materials causes the drill bit to wear unequally, which can jeopardize whatever drilling project you are working on. However, if you use it for a particular material, there is a high tendency that your drill bit will wear equally, allowing it to remain useful for a long time.

5. The speed factors

Speed has always been a significant factor when it comes to drilling, and as such, masons tend to select HSS (High Speed-Steel) tools for their projects. But when it comes to granite drilling, you should choose a tool that strikes a balance between speed and efficiency. As we stated earlier, too much speed can cause friction, which can invariably ruin your project.

A drill bit in fast motion
Figure 5 – A drill bit in fast motion

Also, you should select the granite core drill bits that match the RPM of whatever driller you’re looking to purchase. HSS drills tend to break when the friction becomes too much, and this isn’t good as it makes them less durable. Diamond core drill bits are strong enough to match the RPM of most drilling machines. In this regard, we advise that you purchase diamond core drill bits as they can match most speed levels.

6. Whether it needs finishing

If you’re looking to drill granite, then one aspect you should take seriously is the finishing. This finishing also influences your choice of a drill bit. Builders use granites to design and build many wares ranging from kitchen slabs, floor and wall tiles, bathtubs, and the likes. Some granite core drills finish products very nicely. Some drill bits don’t core drill bits don’t have this feature, why?

Well, diamond core drills come in different shapes and sizes, as you can use them to drill holes for various purposes. These purposes range from wiring, drilling for water, pipe installation, and the likes. So, if you are training your granite material for any of these purposes, then you can afford to pay less attention to the finishing. However, if you’re looking to have a smooth finish, then you should choose the right the core drill bit, which would invariably give you an excellent finish.

If you’re looking to purchase diamond drill bits that give smooth finishes, then NC Cutting Tools are your go-to manufacturers for such tools.

Frequently asked questions

There are numerous questions masons or handymen might have, and we will be reviewing some of them –

1. What are the available granite drill bits?

There are several granite drill bits available in the market ranging from auger drill bits, corkscrew drill bits, spade-like drill bits, and the likes. You can use these drill bits for different drilling purposes. Depending on your granite project and what you’re looking to achieve, you can pick from the available selection in the market. You will find a variety of core drill bits for granite at NCCutting Tools.

2. Can I use a granite drill bit on other materials?

Granite drill bits are usually strong, and as such, you can use them on other hard materials. However, using your granite drill bits on other materials tend to make the drill bits wear quickly. We advise that you use a particular drill bit for your granite drilling project, as this will make it durable.

3. Where can I get the best granite drill bit?

There are numerous granite drill bits available in the market. However, we recommend that you get your granite drill bits from NCCutting Tools as they are a reputable manufacturing diamond tool company. You can look them up on Google and check out some of the reviews and testimonies from their customers.

Final thoughts

By now, you should know the factors to consider when selecting or purchasing a granite drill bit for your project. These tips would go a long way in ensuring that you don’t make mistakes when purchasing granite drill bits.

We also recommend that you purchase your granite core drill bits and other diamond cutting tools from NCCutting Tools as they have a reputation for manufacturing topnotch tools.

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