How to Drill a Deadbolt Lock Into a Metal Door

Measure 4 to 6 inches above the doorknob on the face of the door and make a pencil mark. Use a square and make a line on this mark perpendicular to the edge of the door. Measure 2 ¾ inches from the edge of the door and make a mark on this line. Note that this will be the center of the deadbolt cylinder assembly.

Extend the perpendicular line across the edge of the door. Measure the thickness of the door and make a mark at the center. Note that this marks the center of the deadbolt latch assembly.

Place the point of a nail or an awl on the mark made on the door face indicating the deadbolt center. Tap the nail or awl with a hammer to make an indentation. Repeat this process to make an indentation on the mark indicating the latch on the edge of the door.

Attach a 2 1/8-inch hole saw to a hole saw mandrel using the retaining screws on the mandrel. Tighten the screws with a Phillip screwdriver. Insert the opposite end of the mandrel into a power drill and tighten the chuck.

Place the tip of the pilot bit of the hole saw on the indentation. Hold the drill so that the saw is perpendicular to the face of the door. Start the drill on high speed and bore through the face of the door until the pilot bit pokes through the opposite side of the door. Shut off the drill and remove it.

Insert the pilot bit of the hole saw into the hole made by the pilot bit on the opposite side of the door. Hold the drill so that the saw is perpendicular to the door. Bore through the remaining thickness of the door. Remove the saw.

Remove the hole saw from the drill and install a 7/8-inch hole saw in its place. Place the point of the pilot bit of the hole saw into the indentation on the edge of the door for the deadbolt latch. Hold the drill so that the saw is perpendicular to the edge of the door. Start the drill and bore through the door until you intersect the larger hole drilled on the face of the door. Stop the drill and remove it.

Smooth the rough edges of the holes with a file.