Increasing size of drill holes in tile

[Dr Nick Riviera]

Hi,

I have some holes in tiles that were drilled for studs to support some shelves. Unfortunately the holes are slightly too small for 5mm studs. What's my best bet to increase the size?

Using a normal drill seems unlikely to work and risks the tiles breaking.

Could I maybe use a file? There aren't very many holes so wouldn't think it would take too long but not sure whether a file that will work for tiles and is that small exists.

Would really appreciate any suggestions.

Thanks

 

[geraldthehamster]

Use a drill bit intended for tiles, and go slowly.

Cheers
Richard

 

[vinn]

google "tile drill bits" and you will have a selection to choose from.
The best bits for your purpose would be spade bits.
Drill down from the face of the tile and open up the biscuit from the back.
Constantly cool the tip in water.

 

[Doggit]

Whist a "tile drill" will always be best, an ordinary masonary drill bit will also work, just take it slowly until it gets down below the surface, and don't use the hammer action. And as Vinn points out, like a tile drill, it'll also get hot, so keep dipping it in a cup of water to cool it down.

 

[Dr Nick Riviera]

Thanks a lot for your responses.

I specifically want to make existing drilled holes larger though and was under the impression from reading things online that it's really difficult/impossible to make an existing hole larger without special tools because the drill bit hasn't got enough to grab hold of and you risk slipping.

Any thoughts?

Thanks.

 

[vinn]

I know what you propose and I answered with enlarging the existing hole in mind.
Dont use a tungsten/masonry bit it will possibly shatter the tile.
Use a spade bit but first practice on any offcuts of tile.

 

[Doggit]

Let's get specific; what size are the current holes, and what do you want to get them to. If you've already got a hole, then the next size up will just rest onto the lip of it; as long as you don's use a masonary bit on the hammer action, it'll go in fine. What you've read online, relates more to starting the hole off, as tiles are so hard, you either need a piece of masking tape to help start, or make a starting hole in the glaze with a sharp tap from a hammer and nail. I've done it before, so I know it works.

 

[Chud]

If you're really worried you can use a diamond grit bit in a dremel to enlarge the hole a bit.

 

[L95]

Assuming the tile is ceramic then spade bit, if porcelain then you would struggle with a spade so you should try a diamond tipped drill bit designed for porcelain and natural stone tiles. Both will need to be kept cool using a cup of water unless you have a Rubi Dry Gres bit lying around.