How to Drill Into Tile, Glass, and Ceramic Without Cracking It

Drilling into drywall is forgiving. Drilling into tile, glass, or ceramic is not. There’s a special kind of heartbreak that comes from hearing that faint tick halfway through a hole, pulling the bit out, and finding a hairline crack running from your hole to the edge of a $6 tile — or worse, across the whole backsplash you’ve already installed.

The good news: this is a technique problem, not a talent problem. Once you understand why hard surfaces crack and how to keep heat and vibration under control, drilling into tile and glass becomes one of the most satisfying little skills in your toolbox. Here’s the full method, including the bits to use, the mistakes to avoid, and what to do differently for glass, porcelain, and stone.

Why Tile Cracks in the First Place

Tile doesn’t fail because you pushed too hard (though that doesn’t help). It fails because of three things happening at once: heat, vibration, and uneven pressure.

When a twist bit grinds against glazed tile, it doesn’t cut the way it cuts wood — it rubs. That friction builds heat fast, and ceramic expands unevenly around the hot spot. At the same time, the bit is chattering at the surface, hammering the brittle glaze in tiny impacts. Press hard, and you’re bending the tile against the wall behind it. One of those three — usually heat combined with a little flex — starts a crack, and cracks in tile don’t stop politely.

That explains the whole technique: keep the bit cool, kill the vibration, and let the bit do the work. Everything below is just that principle in different clothes.

The Right Bits (This Is Where Most People Go Wrong)

Regular twist bits and masonry bits are the wrong tools for tile and glass. A twist bit is designed to dig into material with its point and screw its way in — on a hard glazed surface it just skates around and scratches. A masonry bit in hammer mode is even worse: the hammering action exists to shatter concrete, and it will shatter your tile just as happily.

You need one of these:

Diamond hole saws. The best choice for clean holes, especially for anything bigger than about 1/4 inch — shower fixtures, plumbing escutcheons, pipe penetrations. These are hollow cylinders with diamond grit bonded to the rim, sized for common diameters. They grind rather than cut, and the diamond grit stays effective as long as you keep it cool. For a bathroom renovation, a set of four or five common sizes covers almost everything.
Carbide-tipped spear (glass and tile) bits. Cheap, sold everywhere, and perfect for small holes — mounting towel bars, toilet paper holders, small wall anchors. The spear point doesn’t wander the way a twist bit does, and the carbide tips handle glazed surfaces well. Buy them in the exact sizes you need; they’re consumables, and a dull spear bit is a crack waiting to happen.
Solid diamond core bits. For frequent work in porcelain or natural stone, solid (non-segmented) diamond bits last far longer than cheap hollow hole saws. Worth it if you’re tiling a whole bathroom; overkill for hanging one soap dish.

Whatever you choose, check it’s sharp. If your bit has already done twenty holes in porcelain tile, retire it. Dull bits generate heat instead of cutting, and heat is the enemy.

Set Up the Drill Correctly

Two settings matter enormously, and one of them is a deal-breaker:

Turn the hammer action OFF. Say it again for the people in the back: no hammer mode on tile, glass, or ceramic. The hammer mechanism exists to pulverize masonry, and it will pulverize your tile. Use regular rotary drilling only. If your drill doesn’t have a hammer setting to disable, any ordinary drill driver is perfect — you don’t need a hammer drill at all for this job.
Keep the speed low. Aim for roughly 400–800 RPM for small bits, slower for larger diamond hole saws — some manufacturers suggest 200–400 RPM for big diameters. The instinct to rev the drill is backwards here: high speed just cooks the bit and the glaze. Slow, steady, and cool wins every time.

A cordless drill driver is the ideal tool. It’s light, you can control it one-handed while your other hand feeds water, and the variable-speed trigger gives you fine control. A big corded hammer drill is heavy, aggressive, and has a clutch of liability features you don’t need.

Mark the Hole and Keep the Bit From Wandering

The slick glaze on tile is a skating rink for a drill bit, so don’t try to start drilling on bare glaze.

The masking-tape trick. Put two small pieces of masking or painter’s tape in an X over your mark and mark again on the tape. The tape gives the bit something to grip, and as a bonus it supports the glaze around the hole so it’s less likely to chip when the bit breaks through. This is the single highest-value trick in this article.
Make a starter divot. With a spear bit, you can start the hole by hand — press and twist the bit against the mark like a hand drill to scratch a small starter point in the glaze before you power up. For diamond hole saws, you can start the cut at a slight angle — touch one edge of the saw rim to the surface, let it bite a crescent-shaped groove, then slowly tilt upright. That groove keeps the saw from walking.
Drill from the finished side. Always drill from the glazed/visible face toward the back. The exit side is where chipping happens, and you want the chipping hidden behind the tile, not on the surface you look at every day.

The Technique: Cool, Slow, Light

This is the whole game, and it fits in one paragraph: keep the work wet, keep the bit slow, and use almost no pressure. Let the diamonds grind. Your job is to hold the drill straight and feed water — the bit does the cutting.

Water is non-negotiable. This is the step beginners skip, and it’s the step that matters most. The diamond grit on the bit has to stay cool, and the hole has to stay wet so the bit is grinding in a slurry instead of dry-scorching the glaze. Have someone dribble water onto the hole while you drill, or use a sponge soaked in water pressed against the bit. Some pros drill inside a small dam made of plumber’s putty filled with water. On a vertical wall, a spray bottle works — spritz every few seconds. When the hole goes dry, stop. A dry diamond bit overheats in seconds.
Use light, steady pressure. You’re not forcing the bit through; you’re letting it grind. Press hard and three bad things happen: the bit flexes, the tile flexes against the wall, and the heat spikes. Keep your elbow loose, hold the drill straight, and let the weight of the drill do most of the work.
Clear the dust. Every few seconds, back the bit out slightly and let the water flush the debris. Ground ceramic dust in the hole acts like sandpaper under the bit and accelerates heat buildup.
Expect it to take a minute. A 1/4-inch hole through a wall tile takes maybe 30–60 seconds of actual drilling. A 1-inch diamond hole saw through porcelain can take several minutes. Rushing it is how tiles crack. Put on a podcast.

Drilling Glass Is the Same Skill, With One Extra Rule

Everything above applies to glass — drill bits for glass are the same diamond and carbide tools — with one critical addition: glass has no forgiveness for uneven pressure. A tile is glued to a wall that supports it; a piece of glass is floating, and flex is its enemy. Support the glass fully on a flat, cushioned surface (a piece of foam, a towel, a scrap of plywood), and drill from the side that will be visible, for the same exit-chipping reason as tile.

Go even slower on glass than on tile, keep it even wetter, and never let the bit poke through unsupported — back the glass with a sacrificial piece of wood so the exit happens into something solid. If you’re drilling tempered glass, stop: tempered glass cannot be drilled at all. It will shatter into a thousand pebbles the moment the bit bites. (You can tell tempered glass by the etched stamp in the corner, and by the fact that it breaks into cubes instead of shards.) Laminated or annealed glass drills fine; tempered glass doesn’t, ever.

Porcelain vs. Ceramic vs. Stone: What Changes

Ceramic (standard wall tile) is the softest of the bunch. It’s porous under the glaze and drills easily with carbide spear bits and modest care.
Porcelain is denser, fired hotter, and much harder — that’s why it’s the go-to for floors and showers. Carbide spear bits struggle and dull fast on porcelain; this is diamond-bit territory. Expect drilling to take noticeably longer, and be extra generous with water.
Natural stone (marble, granite, travertine) varies wildly. Soft travertine and marble drill like hard ceramic; granite is brutally hard and needs diamond bits, patience, and sometimes a second bit. Watch for natural veins and fissures in stone — they can split under vibration. If the hole lands on a visible vein, consider moving it.
Vitreous/china and porcelain fixtures (toilets, sinks) drill like thick porcelain, but only attempt it if you truly must — fixtures are expensive, and a crack is a replacement, not a re-tile. Most fixtures have pre-drilled mounting holes for exactly this reason.

Anchoring Into What You Just Drilled

Drilling the hole is only half the job. Most tile drilling is for mounting something, and the anchoring matters:

Size the hole for the anchor, not the screw. Plastic expansion anchors need a snug hole — measure the anchor body, not the screw diameter.
For heavy loads on tile (grab bars, towel warmers), consider toggle bolts through the tile into the wall behind. Tile itself carries weight poorly; the structure behind it carries the load.
Drive anchors gently. Hammering a plastic anchor into a tile hole with a mallet sends shock waves straight into the glaze. Push it in, and if it’s tight, twist it in by hand.
Seal bathroom holes. Dab a little silicone around the anchor before you seat it so water can’t migrate behind the tile.

The Five Mistakes That Crack Tiles

Hammer mode left on. The single most common cause of cracked tile, and the one that turns a careful job into instant rubble.
Dry drilling. Ten seconds of dry diamond drilling can overheat the glaze enough to crack it. Water is the whole strategy.
High speed. Fast doesn’t mean quick — it means hot. Slow RPM, steady hand.
Leaning into it. Body weight belongs on the ladder, not the drill. Heavy pressure flexes the tile and spikes the heat.
A dull bit on a hard tile. Retire worn bits. The $8 replacement is cheaper than the tile.

When to Call It

If the tile you’re about to drill is already loose, sounds hollow when tapped, or the hole lands within an inch of a tile edge, you’re working with stacked odds. A hollow-sounding tile has no backing to support it, and holes near edges concentrate stress in the weakest part of the tile. Sometimes the right move is to drill the grout joint instead, use an adhesive mount, or accept that this particular hole isn’t worth the risk.

But for the normal case — a sound tile, the right bit, water, low speed, light pressure — drilling into tile is genuinely easy. The first hole feels terrifying. The tenth feels routine. Keep the bit cool, keep the drill slow, and the tile stays whole.