How to Drill Holes in Quartz Countertops

Installing a kitchen sink or fixtures into a quartz countertop often requires drilling holes into the quartz. Quartz is an extremely hard engineered stone, making it challenging to drill holes without special tools and techniques. With proper preparation and the right methods, drilling quartz can be done successfully.

Gathering the Right Supplies

Drilling holes in quartz requires using diamond drill bits and water. Here are the recommended supplies:

  • Diamond core drill bits specifically for stone – these are different from regular wood/metal drill bits. Use a bit with 1/4″ shank. Sizes are based on the fixture. For a kitchen faucet, use a 1-3/8″ bit.
  • Variable speed drill – A regular power drill on slow speed works. Variable speed functionality helps control rpm.
  • Water and something to catch it – Running water or a spray bottle to keep the diamond bit wet during drilling prevents overheating. Have towels or a bucket handy to catch water.
  • Masking tape – Helps mark the spot to drill and prevent scratched.
  • Safety gear – Goggles and mask to prevent inhaling stone dust.

Preparing the Countertop

Proper preparation is crucial for a clean hole in quartz:

  • Mark the hole location using painter’s tape rather than permanent marker.
  • Check below the countertop for clearance to avoid hitting anything underneath like plumbing or framing.
  • Clear the area of any items that may obstruct drilling. Remove sink basins or cooktops if needed.

Steps for Drilling the Hole

Follow these best practices for smooth, safe quartz drilling:

  1. Tape the drill spot. Cover the exact drill location with masking tape. This helps the bit grip and not skid around causing scratches.
  2. Run water over the bit. Have a spray bottle handy or place a shallow pan of water under the spot to be drilled. Keeping the bit wet prevents overheating and cracking.
  3. Drill at a low RPM. Quartz drilling requires patience. Set the drill to the lowest speed, usually around 600-800 rpm. High speeds can burn the diamond bit.
  4. Make a pilot indentation. Hold the wet diamond bit to the quartz and gently twist it in place without hammering to make a small indentation. This gives the bit a starting place.
  5. Drill slowly. Ease the bit straight down into the stone while spraying or dripping water into the indentation. Apply light, even pressure. Let the drill do the work.
  6. Periodically lift the bit. Every 30 seconds, lift the drill up and down to help clear debris out of the hole. Continue spraying water.
  7. Drill through the countertop. Once the top side has been penetrated, finish drilling slowly through the underside until the hole is complete.
  8. Rinse away debris. Remove all excess stone dust from the hole. Wipe clean with a wet rag. If needed, use a granite polish compound on soft cloth to smooth the cut edge of the hole.
  9. Remove tape. Carefully peel off tape from the area. Avoid pulling too quickly to prevent chipping the quartz around the hole.

Tips for Clean, Successful Holes

Follow these important tips throughout the quartz drilling process:

  • Take your time and don’t rush through the drilling – patience is key!
  • Keep an even pressure and speed to avoid cracking.
  • Always keep the diamond bit wet to prevent overheating, smoking, or cracking.
  • Lift drill up regularly to clear away debris from the hole.
  • Use a larger bit than needed for fixtures to allow room for adjustments.
  • Practice first on a quartz remnant or scrap piece to get the hang of drilling speed and pressure.

Potential Problems When Drilling Quartz

Issues that can arise include:

  • Skidding – Not properly taping down can make the bit skid over the surface, causing scratches.
  • Cracking – Drilling too quickly applies too much pressure and can crack the quartz. Always drill on low speeds.
  • Chipping – Rough hole edges due to dull drill bits or applying uneven pressure. Use new bits and gentle pressure.
  • Overheating – Friction without enough water causes the bit and quartz to overheat. Keep the bit flushed with water.

Questions about Drilling Quartz Countertops

How deep should I drill into quartz?

Drill completely through the full depth of the countertop, usually about 1-1.5 inches. This ensures the hole is clear through for proper fixture installation.

What size drill bit do I need for a kitchen faucet?

For a standard kitchen faucet, use a 1-3/8″ diamond bit. Measure your planned faucet size to be sure. Larger bits allow room for adjustments.

Can I use regular drill bits for quartz?

No. Only special diamond core bits designed for stone drilling will work on quartz. Regular metal bits cannot penetrate the hard quartz material.

How can I smooth rough hole edges?

Use a granite polish compound on a soft cloth or felt pad to buff any rough edges around the freshly drilled hole. Take care not to polish too aggressively.

How do I know if I’m drilling at the right speed?

Drill quartz at the slowest speed possible, usually 600-800 rpm. If you smell burning or see smoke, you’re drilling too quickly. Slow down the drill speed.


Drilling neat holes in a quartz countertop is achievable with the proper techniques. By using diamond drill bits, taking it slow, keeping holes wet, and drilling through the entire thickness of the quartz, perfect openings can be made for sinks, faucets, soap dispensers, and more. Just remember to have patience and let the diamond drill do the work at a gentle pace. With caution and the right tools, anyone can drill professional-looking holes in quartz countertops.