Tile Drill Bits: How to Drill Tile Without Cracking It

Drill glazed ceramic tile with a carbide spear-point tile bit, and drill porcelain or natural stone with a diamond core bit. For both, use a slow speed with the hammer setting switched off, stop the bit from skating with masking tape or a guide, keep diamond bits wet, and change to a masonry bit only once you’re through the tile and into the wall behind.

Most cracked tiles come from three mistakes: hammer mode left on, too much speed, or a bit that skated across the glaze before it bit in.

Ceramic vs porcelain: which bit?

Tile	What it’s like	Bit	Speed
Glazed ceramic wall tile	Soft body under a hard glaze	Carbide spear-point tile bit	Slow to medium
Porcelain floor and wall tile	Dense and very hard all the way through	Diamond core bit, used wet	Slow
Natural stone (marble, granite)	Hard, may crack along veins	Diamond core bit, used wet	Slow
Glass mosaic	Brittle	Diamond core or spear-point glass bit, wet	Very slow

Porcelain is the one that defeats ordinary bits: a carbide tile bit that sails through ceramic can take minutes and still not get through porcelain. For a list of diamond bits by size, see best diamond drill bit for porcelain tile. Stone countertops follow the same method, with more care near edges; see how to drill a hole in a granite countertop.

How to drill tile step by step

1. Mark the hole on a strip of masking tape. The tape stops the tip skating and protects the glaze. Keep holes at least about 1/2 in from the tile edge where you can; holes near edges crack more easily.
2. Check behind the tile for pipes and cables before you drill a wall.
3. Set the drill to rotation only. Hammer mode cracks tile.
4. Start the hole:
   • with a spear-point bit, hold it square and start slowly;
   • with a diamond core bit, start at an angle of about 45° so one edge cuts a crescent, then slowly bring the drill upright; or use a drilling guide that holds the bit in place.
5. Keep it cool and wet. Spray or drip water on a diamond bit, or keep a small dam of putty around the hole filled with water. Lift the bit out now and then to let water in.
6. Use light pressure and let the bit do the work. Pushing hard overheats the bit and can crack the tile.
7. Once through the tile, stop. Switch to a masonry bit of the right size for the wall plug and drill the brick or block behind, now with hammer mode if it’s masonry.

Drill size for wall plugs through tile

Drill the tile with a bit the same size as the plug, or one size larger so the plug doesn’t press against the tile and crack it when the screw goes in. Push the plug in until its collar sits behind the tile surface, inside the wall. For sizes behind tile, see the anchor table in masonry drill bits: how to drill concrete and brick.

Cutting vs drilling tile

Drilling makes round holes for plugs, pipes and taps. Straight and L-shaped cuts are a job for a tile saw or a grinder; can you cut tile with a circular saw covers when a saw works and which blade it needs.