What you need to know
Drill the cylinder hole
Drill out the cylinder hole with the 2-1/8 in. hole saw. Use the same setback (distance from door edge to hole center) as the doorknob, either 2-3/8 in. or 2-3/4 in. After the hole saw’s pilot bit pokes through the opposite side, remove the scrap wood protector and finish drilling the cylinder hole from the exterior side.
Chisel a recess for the faceplate
Chisel out the recess for the rectangular faceplate by inserting the bolt latch set into the door and marking the profile of the faceplate onto the door edge. Use a sharp 1-in. chisel to remove enough material to allow the faceplate to be flush with the door edge (usually about 3/16 in.).
Tip: Cut the vertical edges with a utility knife to avoid accidentally splitting the door with the chisel.
Mark the jamb
Mark the jamb for the strike plate and box by coating the bolt end with lipstick (install the cylinder and bolt first). Next, mark the profile of the strike plate on the jamb. Then, drill out for the strike box by drilling overlapping 1-in. holes. Finally, chisel out the recess for the strike box and plate.
Single-cylinder deadbolts (keyed on one side) will work fine for most situations. Double-cylinder deadbolts (keyed on two sides) are a good idea if you have a window near the deadbolt. For safety reasons, if you choose a double-cylinder deadbolt, make absolutely certain your family knows where the key is and leaves it there.Calling a locksmith out for this job will cost $150 or more, but you can install a heavy-duty deadbolt yourself in less than an hour for a third of the price. That's about average for a good deadbolt and a hole saw set. To cut through a steel door, make sure you get a “bimetal” hole saw set.
Use a Grade 1 deadbolt. Deadbolts have a grade rating of 3 to 1 (1 is the toughest). Most home centers carry Grade 1 deadbolts, such as Schlage's Maximum Security Deadbolt, but you may have to hunt for them. Expect to pay $27 to $35 for a Grade 1.
Install a strike box. A strike box strengthens the deadbolt by spreading the impact of a forced entry over a wider area and by helping tie the strike to the 2x4 frame, not just the jamb. You can get a separate strike box for about $7 at home centers.
Use the rectangular faceplate. Most deadbolts allow you to choose between a rectangular faceplate and a round one that doesn't require chiseling. Unless you have a steel door, don't be tempted! The rectangular faceplate, recessed into the door, makes a stronger setup.