Which drill bit should I use for tile?
Which drill bit should I use for tile?
A spear-point carbide or diamond bit in rotary mode only — hammer action shatters tile, every time.
Tile is hard and brittle, and hammer action applies exactly the kind of point impact that propagates a crack across the whole tile. The correct approach is abrasion — a carbide or diamond edge grinding a hole through the glaze — which is slow and generates heat, and heat is the second thing that cracks tiles and destroys bits. Water is therefore not optional on porcelain: a sponge, a plasticine dam or a squeeze bottle keeps the temperature down and flushes the dust out. Starting a hole on a glossy glaze is the other awkward moment, solved with masking tape, a punched-through piece of tape, or a drilling jig with a suction cup. Once through the tile, change to a masonry bit and hammer for the substrate behind.
The options, ranked
| Option | Good at | Bad at |
|---|---|---|
| Spear-point carbide tile bit | Cheap and effective on glazed ceramic wall tile; the ground point breaks the glaze without skating. | Blunts almost immediately on porcelain and will not go through it. |
| Diamond core bit | Cuts ceramic, porcelain and natural stone, and stays sharp for many holes when cooled. | Needs water or regular cooling, and runs slowly. |
| Multi-material bit | Passable on soft ceramic when nothing else is to hand. | Poor centring on glaze and no use on porcelain. |
Technique that changes the outcome
- Rotary mode only, low speed, light steady pressure
- Stick masking tape over the mark to stop the tip skating, or use a suction jig
- Keep the tip cool and wet with a sponge or a plasticine dam of water
- Drill through the tile, then swap to a masonry bit for the wall behind
- Drill into the tile face rather than a grout line if a fixing has to hold weight
What goes wrong
- Hammer mode at any point while the bit is in the tile
- Leaning on the drill to speed things up — it cracks the tile at breakthrough
- Dry-cutting porcelain, which glazes the diamonds and produces silica dust
Compiled practical guidance rather than a published standard. Product formulations vary by brand and market, so read the label — and where the work is structural, electrical or gas, the regulations that apply where you are govern rather than anything here.
Other drill bit questions
| For | Use |
|---|---|
| Metal | An HSS twist drill, ideally with a 135° split point, run slowly with firm pressure and cutting fluid. |
| Concrete | An SDS-plus carbide bit in a rotary hammer — a normal hammer drill will get there eventually and blunt several bits doing it. |
| Masonry | A carbide-tipped masonry bit in hammer mode for brick and block; step up to an SDS rotary hammer above about 10 mm. |
| Porcelain tile | A diamond core bit, cooled with water, at low speed — carbide spear points do not cut porcelain. |
| Stainless steel | A cobalt bit at low speed with heavy constant pressure and cutting fluid — and never let it stop cutting. |
| Wood | A brad point bit for clean holes up to about 13 mm; an auger for depth and a Forstner for a flat bottom. |
| Plasterboard (drywall) | Almost none — an ordinary HSS or brad point bit in rotary mode, and the real question is which fixing goes in the hole. |
| Glass | A spear-point carbide or a diamond bit, run slowly under water — and toughened glass cannot be drilled at all. |
| Plastic | An HSS bit ground to a shallower rake, or a plastic-specific bit, at low speed with a backing board — acrylic especially will crack. |
| Hardened steel | Solid carbide in a rigid setup, or soften the spot first — HSS and cobalt cannot cut anything much above 50 HRC. |
| Aluminium | A sharp HSS bit at high speed with a wax or paraffin lubricant — the problem is aluminium sticking to the bit, not hardness. |
| Large holes in wood | Spade for speed and roughness, auger for depth, Forstner for a clean flat bottom, hole saw for big diameters in thin stock. |
Common questions
- Which drill bit should I use for tile?
- A spear-point carbide or diamond bit in rotary mode only — hammer action shatters tile, every time.
- What should I avoid?
- Hammer mode at any point while the bit is in the tile Leaning on the drill to speed things up — it cracks the tile at breakthrough Dry-cutting porcelain, which glazes the diamonds and produces silica dust
Related pages
- Which drill bit should I use for metal? An HSS twist drill, ideally with a 135° split point, run slowly with firm pressure and cutting fluid.
- Which drill bit should I use for concrete? An SDS-plus carbide bit in a rotary hammer — a normal hammer drill will get there eventually and blunt several bits doing it.
- Which drill bit should I use for masonry? A carbide-tipped masonry bit in hammer mode for brick and block; step up to an SDS rotary hammer above about 10 mm.
- Which drill bit should I use for porcelain tile? A diamond core bit, cooled with water, at low speed — carbide spear points do not cut porcelain.
- Which drill bit should I use for stainless steel? A cobalt bit at low speed with heavy constant pressure and cutting fluid — and never let it stop cutting.
- Which drill bit should I use for wood? A brad point bit for clean holes up to about 13 mm; an auger for depth and a Forstner for a flat bottom.
- Which drill bit should I use for plasterboard? Almost none — an ordinary HSS or brad point bit in rotary mode, and the real question is which fixing goes in the hole.
- Which drill bit should I use for glass? A spear-point carbide or a diamond bit, run slowly under water — and toughened glass cannot be drilled at all.
- Which drill bit should I use for plastic? An HSS bit ground to a shallower rake, or a plastic-specific bit, at low speed with a backing board — acrylic especially will crack.
- Which drill bit will go through hardened steel? Solid carbide in a rigid setup, or soften the spot first — HSS and cobalt cannot cut anything much above 50 HRC.
- Which blade cuts tile? Blade
Sources
- Typical range compiled from manufacturer specifications — At One Place