How to Drill a Pilot Hole
Drilling a pilot hole is often necessary for building projects or when remodeling the home. But do you know how to drill a pilot hole the right way? Selecting the right drill bit and a few other simple drilling techniques are important to drilling the perfect pilot hole.
Why You'll Want to Drill a Pilot Hole
Drilling a pilot hole—sometimes called pre-drilling—isn't necessary if the material is soft enough to screw into directly without damaging the material. But in most cases, pre-drilling a pilot hole is beneficial.
- Prevents wood from splitting
- Helps drive screws near the edge of materials
- Relieves strain on the drill when screwing into dense materials
- Reduces snapped screws and stripped screw heads
- Allows old or fragile materials to be screwed into without splitting
- Predetermines the direction of the screw
Choosing the Right Drill Bit for a Pilot Hole
Choosing the correct size of drill bit to drill the pilot hole is important. If you choose a bit that's too thin, you might end up splitting the wood. If you choose a bit that's too thick, the screw's threads will not grip the wood.
The drill bit should be the same diameter as the screw's shank—not including the screw threads. The shank is the screw's inner core or its shaft.
Wear safety glasses when using a drill.
What You'll Need
Equipment / Tools
- Electric drill
- Drill bits, set
- Wood countersinks, set (optional)
- Material to be drilled
Mark the Material
With the pencil, mark the spot on the material where you want to drive the screw.
Choose the Proper Drill Bit
Select a drill bit that is the same diameter as the screw's shank. First, select a drill bit that looks as close as possible to the correct size. Then, hold the drill bit behind the screw. If you cannot see the drill bit behind the screw, the drill bit is the correct size.
Chuck the Drill Bit Into the Drill
Open the drill's keyless chuck by turning it counterclockwise. The chuck collets, or the three metal arms, will open up. Insert the drill bit. Turn the keyless chuck clockwise to tighten the bit. Make sure that the drill bit is not crooked or misaligned in the collets.
Drill the Pilot Hole
Place the tip of the drill bit on the mark. Start the drill slowly, applying light pressure to the drill. Increase the speed or pressure on the drill only when needed. Drill the pilot hole as deep as the length of the screw.
Withdraw the Drill Bit
With the drill still slowly rotating, withdraw the bit from the hole. Be careful to keep the drill straight to avoid widening the hole. Clear splinters from around the hole before driving the screw.
Tips for Drilling a Pilot Hole
- If you don't have a countersink bit, you can create a cone-shaped depression with a larger-size drill bit. Use the tip of this bit to carve away wood, but stop short of drilling a hole.
- Rubbing the screw threads with screw wax or even ordinary candle wax will help ease the screw into the material.
- Pilot holes aren't commonly drilled for nails. But you can do this if the wood appears that it will crack or if you need to get the nail started at a low angle.
- In some cases, you may be attaching two boards and need the boards to draw tightly together. In this case, the front board's pilot hole should be the total diameter of the screw, threads included. The screw should be able to pass straight through the hole, stopping at the screw head. The back board's pilot hole should be the diameter of the screw shank, so that the threads grab the material.