To install a door strike plate, you must first mark the location of the plate on the door jamb. Next, a hole must be drilled in the jamb to accept the door lock bolt. A mortise, or recess, must be made in the door jamb to accept the strike plate. The mortise needs to be as deep as the strike plate is thick. Finally, the strike plate is screwed in place. Set aside half an hour to complete this task.
Mark the strike plate location. Mark where the lock bolt hits the jamb, and from this point make a cross mark 11/16 inch in from the edge of the jamb for interior doors, or 7/8 inch in for exterior doors. Center the strike plate on this mark, and temporarily screw it in place. Using the utility knife, scribe a line around the strike plate, then remove the plate.
Look for any nail heads in the scribed area. If nails are present, use the nail set and the hammer to drive them deep enough that they won't be hit by the drill bit or the chisel.
Drill a hole on your cross mark. This hole will go all the way through the jamb. Make the hole at least as deep as the length of the door lock's bolt.
Make the mortise for the strike plate using the chisel. Make straight cuts on your scribed line perpendicular to the jamb. Then inside your scribed lines, make a series of cuts, about 1/4 inch apart, equal in depth to the thickness of the strike plate. Using a scraping motion, remove the material from inside the scribe lines.
Screw the strike plate in place.
If you have access to a router, you can mortise strike plates using the router with a template and mortising bit. Make a practice mortise on scrap wood before cutting into your door jamb.
Always wear safety glasses or goggles when using power tools.