Techniques and Tools for Drilling Granite

Understanding how to drill granite is an essential point in our work of exploring various processing techniques. In most cases, the idea is that it will be incredibly difficult to make a hole in the stone known as granite.

This material is fundamentally difficult to work with. It's no wonder that we say "hard as granite". In reality, it's just a common opinion, there are specific solutions for drilling granite without many difficulties. You just need to know the stone and the tools.

What is granite and how it is used

Before we understand how to drill granite and which tools to use, it's right to make a small exploration of the material in question. We're talking about a rock abundant in nature and composed mainly of feldspars, quartz and micas. The color of this stone can vary depending on the components and ranges from white to pink to green and shades tending to black.

The name is connected to its grainy composition, and among its characteristics we find hardness and resistance, so much so that the material in question is often used for flooring, although much depends on the type of granite being examined.

For example, white granite, very common in Italy, can be used for floors and stairs both indoors and outdoors. The same can be said of black granite from Zimbabwe and Sardinian granite, particularly known for its resistance and impermeability qualities.

Why drill a hole in granite?

There could be various requests that lead you to drill a granite slab. Often this request is tied to the need to complete a furnishing job. For flooring we need above all techniques and tools to cut slabs while drilling is more appropriate when aiming for a job of finishing planes and surfaces. For example?

It can be a common need to drill a large hole in the granite slab that serves as a kitchen countertop. Reason? You need to pass the faucet pipes through. All this to remind us of one point: you may need to make holes with different radii in marble and granite, even with rather large diameters. In these cases, specific tools for drilling granite are used.

Which tools to use for drilling granite?

First of all you need to get individual protective devices that can guarantee you safe work. Gloves and protective glasses are the essential starting point to have maximum peace of mind in these circumstances. Then you need to get a drill capable of managing execution speed and specific bits. For example? For ordinary holes you can use the Gres+ from Krino.

This is a bit designed for drilling porcelain stoneware but also most building materials. Its fundamental characteristic is the hard metal insert with diamond sharpening capable of drilling the surface of extremely hard materials just like granite. What are the techniques for drilling granite with this specific bit for hard stone?

The model should be used without percussion, only with rotation, and allows you to make holes in granite with extreme precision: the cut affects the material immediately and avoids slipping risks. It can drill both dry and with water cooling, a condition that allows you to get the best results. It's better to use it at low speed on granite, about 500 revolutions per minute.

To drill the hardest stones like granite, but also concrete and cement, you can use the Super Granit bits in HRC alloy steel and diamond-sharpened insert that work with percussion movement of the drill.

How to make a large hole in granite

If you need a hole with a generous diameter, wider than what you can achieve with a normal bit, you need to use a cup mill. The best solution is the one with diamond profile because it allows you to cut granite with greater precision, without effort. One of the best tools for drilling granite while applying the diameter you prefer (for example that of the faucet)?

We recommend the Keramaster mill, which is characterized by a continuous rim and suitable for cutting tiles and stones such as porcelain stoneware and glazed, marble, granite, ceramic, slate. The larger the diameter, the lower the rotation speed: remember that these tools work well dry but with water lubrication you can have a longer tool life.

Some advice for better drilling granite? First of all you need to work at reduced speeds, especially when operating with large mills. And evaluate the presence of good water lubrication to get a clean result.

But also greater efficiency of the bit. If we're working with an operation to completely drill through the slab it's best to place another similar stone underneath the one to be drilled so that the edge won't be ruined when the bit exits.

A practical tip when you want to drill granite: before drilling a visible surface, maybe the marble of a kitchen or a floor or even a windowsill, work on a non-visible area. If the result doesn't satisfy you, you can always avoid damage.