How to Drill Into Glass

Drilling into glass sounds scary — and it can be if you rush it. But with the right diamond bit, low speed, and water cooling, you can drill clean, crack-free holes in glass bottles, mirrors, aquariums, and glass panels. Here's the complete guide.

Can You Drill Into Any Glass?

Most standard glass can be drilled — bottles, mirrors, glass tiles, and window panes. However, tempered glass cannot be drilled — it will shatter instantly. Check if your glass is tempered before attempting to drill (tempered glass usually has a small etched label in the corner).

What You'll Need

Diamond-tipped drill bit — the only type that works on glass
Variable speed drill (cordless or corded)
Water — to cool the bit continuously
Masking tape or plumber's putty dam
Safety goggles
Non-slip mat or rubber pad — to stabilize the glass

The Right Drill Bit for Glass

You must use a diamond-tipped bit. The Drilax 5/16 inch Diamond Drill Bit Set (5-Pack) is specifically designed for glass, tile, and ceramic — delivers clean, chip-free holes and works great for bottle lamps, planters, and decorative glass projects. Check it on Amazon →

Step-by-Step: How to Drill Into Glass

Place the glass on a rubber mat to prevent slipping and reduce vibration.
Mark your spot with a marker.
Apply masking tape over the mark to prevent the bit from skating.
Create a water dam: Roll plumber's putty into a ring around your drilling spot and fill with water — this keeps the bit cool throughout drilling.
Put on safety goggles.
Set your drill to the lowest speed — high speed will crack the glass.
Do NOT use hammer mode.
Start at a 45° angle to create a small groove, then slowly bring the drill to 90°.
Apply very light pressure — let the diamond bit do the cutting.
Keep the bit wet at all times — add more water as needed.
Slow down as you near the exit point — this is when chipping is most likely.
For bottles: Fill the bottle with water to the drilling level for built-in cooling.

Pro Tips

For glass bottles, drill from both sides — drill halfway through, flip, and finish from the other side to minimize chipping
Never let the bit run dry — heat is the enemy of glass drilling
Use a drill press if available for perfectly perpendicular holes
Practice on a scrap piece of glass first

Safety Tips

Always wear safety goggles — glass chips are extremely sharp. DEWALT DPG84 Goggles →
Wear work gloves when handling drilled glass. HANDLANDY Work Gloves →
Never drill tempered glass — it will shatter dangerously
Keep water away from electrical connections

Common Mistakes to Avoid

Using a regular or masonry bit on glass
Drilling at high speed
Using hammer mode
Not keeping the bit wet
Pressing too hard
Attempting to drill tempered glass

Back to blog