Drilling Holes for Locks in a New Wood Exterior Door

Measure four to six inches -- depending on your preference -- above the existing doorknob and mark a line that is perpendicular to the edge of the door. Extend this line over the edge of the door with a square. Measure and mark a centerline that is two and three-quarter inches away from and parallel to the edge of the face of the door and intersects the previous line at a 90-degree angle. Note that where the lines meet will be the center of the hole for the deadbolt lock cylinder.

Insert the shank of a 2 1/8-inch-diameter hole saw into a power drill and tighten the chuck.

Place the point of the center pilot bit of the hole saw onto the intersected marks. Hold the drill so that the saw will penetrate the door in a perfectly level position. Start the drill and bore a hole halfway through the door. Remove the saw and drill from the door. Insert the pilot bit into the hole on the other side of the door made by the pilot bit. Drill through the second half of the door with the saw. Remove the saw from the door.

Measure the center of the edge of the door over the perpendicular line you extended over the edge previously and make a mark. Note that this point is where the smaller hole for the deadbolt latch assembly will be drilled.

Remove the hole saw from the power drill. Install a 7/8-inch spade bit into the drill. Place the point of the bit onto mark on the edge of the door. Hold the drill level so that the drilled hole will be straight. Drill through the edge of the door until the bored hole intersects the larger hole drilled in the face of the door previously. Remove the drill from the door.

Use a file to smooth out any rough edges around the holes.