How to Drill Through Quartz Countertop

Understanding Quartz Countertops

Quartz countertops, sometimes referred to as engineered stone, are made from ground natural quartz crystals combined with resins and pigments. This makes quartz tougher and more durable than natural stone counters like granite or marble.

Some key properties of quartz that affect the drilling process:

  • Extremely hard – quartz has a Mohs hardness rating of around 7 out of 10, making it harder than granite.
  • Non-porous – quartz lacks the pores and fissures found in natural stone, resulting in a dense, even surface.
  • Brittle – while very hard, quartz can chip or crack if drilling pressure is applied unevenly.

Choosing the Right Drill Bit

The key to drilling quartz successfully is using the proper drill bit. Avoid standard twist bits, as they will wear down rapidly and overheat on quartz’s hard surface. Here are the best options:

  • Diamond core drill bits – These industrial-grade bits with diamond abrasive surfaces are ideal for quartz. Look for one designed specifically for stone/tile.
  • Tungsten carbide drill bits – Nearly as hard as diamond, these are a less expensive option than diamond core bits. Select bits made for masonry or tile.
  • Titanium drill bits – Not as durable as diamond or tungsten bits, but titanium works better than standard bits. Look for titanium masonry/tile bits.

Aim for a drill bit diameter between 1/4″ to 1/2″ for most quartz countertop holes. Larger diameter bits over 1/2″ can be prone to breaking quartz.

Using the Proper Tools

Along with the right drill bit, you need the proper tools:

  • Variable speed drill – Use a cordless drill with adjustable speed and torque settings. This gives control over drill speed.
  • Water – Keeping the drill site wet avoids overheating the quartz. Have a spray bottle of water handy.
  • Tape – Masking tape over the drill site reduces bit slippage that can crack quartz.
  • Jigsaw – For larger holes, a jigsaw with a diamond blade can cut openings in quartz.
  • Masks and eye protection – Wear safety gear to protect yourself from flying debris when drilling.

Drilling Steps

Follow these steps closely when drilling into quartz:

1. Mark the Drill Site

Use a permanent marker to mark the desired hole location. If drilling near an edge, stay at least 1 1/2″ away.

2. Prepare the Surface Area

Clean the drilling area of any dirt or residue. Then apply masking tape over the mark to prevent bit slipping.

3. Start Drilling at a Low Speed

Set your variable speed drill to the lowest speed setting. Position the bit perpendicular to the surface and gently begin drilling.

4. Apply Light Pressure

The bit should penetrate the quartz without much force. Let the diamond or tungsten bit do the work by just applying light pressure.

5. Frequently Spray Water

Stop drilling regularly, remove the bit, and spray water over the drilling point to cool it down. The water prevents overheating.

6. Advance the Bit Gradually

Gently drill only about 1/4″ to 1/2″ deep before pausing to spray more water. Repeat, advancing the bit gradually with patience.

7. Drill from Both Sides

For holes wider than 1″, it helps to drill half from each side to prevent cracking as the hole breaks through.

8. Clean Up Debris

Use a wet cloth to wipe away all quartz dust and particles left over after drilling. Check the hole edges for any cracks or chips.

Troubleshooting Drilling Issues

Problem: Bit slips and scratches the surface

Solution: Ensure the drill site is taped down to prevent bit movement.

Problem: Quartz cracking around the hole

Solution: Use lighter pressure and lower speed. Spray with water more frequently.

Problem: Hole edges chipping

Solution: Upgrade to a higher quality diamond or tungsten carbide drill bit.

Problem: Overheating and burning

Solution: Drill at the lowest speed setting and pause frequently to spray water on the bit.

Drilling Holes Safely in Quartz

Drilling through quartz countertops is possible if done carefully with the proper drill bits and techniques. Always use a variable speed drill at the lowest setting and drill gradually to avoid cracking or overheating. Taking it slowly with this hard material is key for clean, safe holes. With the right diamond or tungsten carbide bit and ample water cooling, you can drill the custom holes you need in quartz countertops.

Frequently Asked Questions

What size drill bit is best for drilling through quartz?

For most standard holes, a 1/4″ to 1/2″ diamond core or tungsten carbide masonry bit is ideal. Larger diameter bits over 1/2″ are more prone to damaging quartz.

Is using a hammer drill recommended for quartz?

No, hammer drills are not recommended as the impact function is too aggressive for quartz. The rapid hammering motion is likely to crack or shatter the hard but brittle material. Stick to a variable speed regular drill.

What speed setting should the drill be on for quartz?

Always start drilling quartz at the lowest speed setting, usually around 400-600 RPM. Slow speeds let you advance through the hard material safely. Increase the speed slightly once a hole is established.

How much pressure should be applied when drilling quartz?

Very little direct pressure. Let the drill bit do the work. Apply just enough light pressure to gently penetrate the surface and advance the hole. Too much force risks cracking the quartz.

How can I prevent a drill bit from slipping on quartz?

Masking tape provides the best grip. Make sure to tape over the marked drilling site before starting to prevent the spinning bit from sliding across the smooth quartz surface.

Is drilling quartz countertops safe as a DIY homeowner project?

It can be, with caution. Use eye and hand protection. Follow drill speeds and pressure recommendations carefully to avoid cracking the quartz. Consider hiring a pro if you don’t have the proper variable speed drill and drill bits.

Can I use a regular household drill for quartz?

It is not recommended. Average homeowner drills do not have variable speed triggers needed to start slowly and ramp up gradually. Specialized masonry drill bits are also required for quartz’s hardness.

What can I do if my quartz cracked while drilling?

Unfortunately, once cracked there is no good repair option. The cracked section will likely need to be replaced. To prevent cracking, keep drill speeds low, use a spray bottle for lots of water, and do not apply heavy pressure.


Drilling holes in quartz countertops is doable with patience and the right techniques. Be sure to use the proper tungsten carbide or diamond core drill bits and a variable speed drill starting at the lowest RPM setting. Applying minimal pressure while providing ample water cooling allows holes to be drilled smoothly without cracks or burns. Taking it slow and easy is key to success when drilling through ultra-hard quartz. With the right tools and proper methods, you can add custom holes to quartz for faucets, soap dispensers, and other attachments.