installing my APEC ROES-50, can I drill through granite for the faucet? what size bit?

Diagnosis

Drilling through granite for the APEC ROES-50 faucet is a high-risk operation because granite is an igneous rock with a high quartz content, making it extremely hard and brittle. Unlike laminate or acrylic, granite cannot be cut with standard high-speed steel (HSS) or titanium bits; attempting to do so will result in the bit overheating, dulling instantly, and potentially cracking the countertop due to excessive pressure or thermal shock. The primary challenge is the "bite" of the drill. Because granite is non-porous and slick, a standard bit will skate across the surface, leaving permanent scratches on your stone. To successfully install the faucet, you must use a diamond-core hole saw. This process removes a cylinder of stone rather than grinding it away, which minimizes the risk of fracturing the slab. Confirmation of the correct tool is simple: if the bit does not have a diamond-grit coating on the cutting edge, it is not suitable for granite.

How to Fix It

To install the standard ROES-50 faucet, follow these precise steps to ensure a clean hole without cracking the stone:

1. Select the Correct Bit: For the standard APEC faucet, use a 1/2" diamond-core hole saw. If you have upgraded to an air-gap faucet, you will need a 1 1/4" diamond-core bit.
2. Prepare the Surface: Place a piece of masking tape or a painter's template over the drilling area. This prevents the drill bit from "walking" or skating across the granite during the initial start.
3. Set Up Water Cooling: Granite drilling requires constant lubrication to prevent the diamond edge from burning out. Use a spray bottle with water or have a helper continuously drip water onto the drilling site.
4. Initial Angle Entry: Start the drill at a 45-degree angle to create a small "notch" or indentation in the stone. This provides a seat for the bit and prevents it from sliding.
5. Vertical Drilling: Once the notch is established, bring the drill to a 90-degree angle. Use a variable-speed drill set to a medium speed. Do not apply heavy downward pressure; let the diamond grit do the work.
6. Clear Debris: Periodically lift the bit slightly while it is spinning to allow the water to flush out the granite slurry (grey paste) from the hole.
7. Final Pass: As you feel the bit break through the bottom of the slab, reduce pressure significantly to avoid "blowout" (chipping the underside of the granite).

If That Didn't Work

• Professional Installation: If you encounter a "vein" of harder mineral or the stone begins to spider-web, stop immediately. Contact a local stone fabricator. They use professional-grade wet-core drills that use a vacuum system to manage slurry and high-torque motors that prevent the bit from binding.
• Under-Sink Mounting: If you are uncomfortable drilling the granite, consider mounting the faucet to the sink rim if it is a stainless steel or cast iron model. This avoids the stone entirely and only requires a hole through the metal.
• Diamond Paste/Lubricant: If the bit is overheating despite using water, switch to a dedicated diamond drilling lubricant or a mixture of water and a small amount of dish soap to reduce surface tension and improve cooling.
• Bit Replacement: If the bit stops cutting and simply spins, the diamond segments have likely glazed over. You can sometimes "dress" the bit by drilling through a piece of scrap abrasive stone or replacing the diamond core entirely.

Heads Up

• Avoid Hammer Drills: Never use the "hammer" or "percussion" setting on your drill when working with granite; the impact will shatter the stone's internal structure and cause a full-length crack.
• Check for Underside Clearance: Ensure there are no plumbing pipes, supports, or electrical wires directly beneath your drilling point before starting.
• Seal the Hole: After drilling and installing the faucet, apply a small bead of clear 100% silicone sealant around the base of the faucet where it meets the stone to prevent water from seeping into the cabinetry below.
• Safety Gear: Always wear safety goggles. Granite shards are like glass and can fly off at high speeds during the breakthrough phase.