How to drill a tap hole in granite sink?

Question

Hi Team,

I need to drill the tap hole in my granite sink. There is a pre drilled hole already.

I visited my local store today but unfortunately no one was available to answer which drill bit

I should purchase to complete this task. one has teeth and the other does not.

Hoping for some help.

JoWhato · Answer

Thanks guys this is very helpful, I ended up buying the hole saw with shank. Fortunately, the sink already has half a predrilled hole. :-)

Nailbag · Answer

Hi @JoWhato

My first tip before following my guide using the same holesaw, is if at all possible practice first. Its very nerve-racking the first time, especially as these cutters don't have a pilot hole to guide you.

Two hands is the key on a decent powered drill for control and rotating the edge all the way around of the saw until you have 360deg started into the cut. Then slowly work your way into a vertical even cut to complete the cut.

As per my instruction, have an old tool underneath the stone so at breakthrough the muddy water doesnt go into the shelf.

Nailbag

JacobZ · Answer

Hi @JoWhato,

Apologies that you couldn't get your question answered in store, please allow me to help.

I'll start by saying that drilling through stone benchtops should be done with extreme caution. Ensure you wear the appropriate PPE including a P2 mask or higher, hearing and eye protection and ensure you wet the drill bit down to prevent overheating.

I'd also suggest you have a read of @robchin's comment in the following discussion -

https://www.workshop.bunnings.com.au/discussion/229196/how-to-drill-a-hole-in-granite-benchtop

As well as @Nailbag's guide -

https://www.workshop.bunnings.com.au/discussion/229181/how-to-make-holes-in-ceramic-tiles-stone-benchtops-cement-sheeting

Now, with the hole saws, there is a very slight difference in how they cut, but not a great deal. Both would work for this purpose as long as you have a suitable strong drill for the application, you take it nice and slow and apply water to the teeth of the bit while cutting.

The main difference besides the teeth, is that the

https://www.bunnings.com.au/kango-35mm-diamond-pro-diamond-hole-saw_p0354500

requires this

https://www.bunnings.com.au/kango-32-114mm-diamond-holesaw-arbor-with-retractable-starter-bit_p0097103

to attach it to a drill, whereas the

https://www.bunnings.com.au/kango-35mm-mini-diamond-pro-hole-saw_p0022193

has a hex shank built in.

Of the two, I would go with the toothed hole saw and purchase an arbor separately. Combined, the price is still cheaper than the mini diamond hole saw.

Make sure you wear your PPE, take it nice and slow and keep the tip wet while drilling to prevent overheating.

Let me know if you have any further questions.

Jacob