drill bit - 20mm in porcelain

[magpies]

Hi, I need to drill 2no, 20mm holes in a porcelain tile for a shower valve. What is the best (budget friendly?) drill bit and where to purchase?

[megaphone]

I'd use a hole saw for 20mm. One that can cut ceramics. Something like this, although I have not used these myself

https://www.screwfix.com/p/titan-wet-diamond-holes...

[MajorMantra]

Yep something like that, suspect they are much of a muchness. To drill you start on one edge and then rotate the bit into the cut. Don't try drilling perpendicular from the start because you'll just skate across the surface.

[megaphone]

Yes I noticed the ones I linked to do not have a pilot drill like other hole saws have, so care needed when drill

[RotorRambler]

I used the above, to drill holes in porcelain tiles, for the pipes to shower valve.
Work fine but it s a slow process, thankfully my measurements were correct in a 1200 x 800 tile!
Have a dry run on a spare if you can.
I found it best to start at a slight angle to break the glaze, then slowly does it. (beaten to it above!)
Water too to cool it.

[Road2Ruin]

MajorMantra said:

Yep something like that, suspect they are much of a muchness. To drill you start on one edge and then rotate the bit into the cut. Don't try drilling perpendicular from the start because you'll just skate across the surface.

Just put a criss cross of masking tape over where you want the hole. You don't skid.

[JoshSm]

Rubi & others sell stick on guides to keep a tile hole saw in the right place.

Don't forget that you'll need something to keep a water supply to the cutter while you work, especially on porcelain.

Also don't forget that if you're using a regular drill and wet cutting that you'll really want to check the chuck is dry afterwards as water does them no favours.

[paulrockliffe]

If you can get the tile on a pillar drill for these holes then it is worth it. Still diamond core bits and water, but so much easier that way.

[RammyMP]

It might help to keep a water supply on while drilling to cool the bit and stop it burning out.

[AW10]

Or a pair of helping hands holding a piece of board with a 20mm hole drilled in it.

But ideal is a pillar drill with the tile in a roasting tin or similar half filled with water.

[magpies]

RotorRambler said:

I used the above, to drill holes in porcelain tiles, for the pipes to shower valve.
Work fine but it s a slow process, thankfully my measurements were correct in a 1200 x 800 tile!
Have a dry run on a spare if you can.
I found it best to start at a slight angle to break the glaze, then slowly does it. (beaten to it above!)
Water too to cool it.

Thank you all for your suggestions

RetroR
I am using 1200 x 600 tiles, so definitely do not want to mess this up.
What did you use to cut your tiles - I am looking at a grinderette with new suitable disc and a lightly clamped straight edge as I don't have a tile cutter big enough and cannot hire one.

[Tango13]

I'd be looking for someone local with a waterjet cutting machine and offering them some cash.

[fooman]

Diamond hole drill is the correct way, careful getting started as the drill can skip around and damage tile surface. A bit of tape on the tile can help with this. I used a spay bottle of water and a child squirting the bit every few seconds.

[MajorMantra]

When I did a big tiling job I found a big 'bridge' style tile saw with water jet for around £90 on Marketplace. It's a tool people tend to use once or twice and then move on, so always worth looking for bargains.

[Frane Selak]

I used these off amazon, I thought they would be rubbish but one bit drilled at least 10 holes in various porcelain tiles in my new bathrooms.

https://www.amazon.co.uk/dp/B073LT4PZ9?ref_=ppx_hz...

I used the 18mm bits but other sizes are available. To centre it I got a piece of wood with the same size hole in it and clamped it to the tile in thecorrect place, worked perfectly.