Although a chain Door Lock used on the inside of your home's entry door is not the most secure of locks, it does add an additional level of protection and security when opening your door to strangers or at night. Installing a chain lot will require that you drill into your door and doorframe. Installing this type of lock is easy and can usually be completed in half-hour or less.
Step 1 - Purchase a Chain Lock Kit
Visit your local home improvement store and purchase a chain lock kit. Look for a kit that has a hardened steel chain and has wood screws that are least 2 inches in length. Also, make sure to look at the drill bit size required for the chain lock it. If you do not have the appropriate sized drill bit, purchase one at this time. You will find that most chain lock kits require a 1/4 inch or 1/8 inch hole be drilled. One quarter of an inch screws will offer better protection.
Step 2 - Mark Holes for the Chain Lock
Take the template that is included with the chain lock kit and place it on the door at a height that is suitable for you. In most cases, you'll want to install the chain lock slightly lower than eye level. Use a pencil to mark the holes that will needed to be drilled for the chain lock.
Step 3 - Drilling Holes
Use the appropriate sized drill bit to drill holes for the wood screws that will be used to attach the chain lock to the door and the door frame. Make sure to drill the holes slowly and make sure that the holes are straight.
Step 4 - Install the Chain Mount
Place the chain mount up against the door frame and align the screw holes. Make sure the edges of the chain mount are parallel with the doorframe and are aligned evenly. Next, take the wood screws that are included with the kit and slowly screw them in. Make sure to tighten the screws securely, but do not over tighten as this may cause the screw to strip or damage the doorframe.
Next, align the lock plate with the holes that you drilled in the door. Again, make sure that the lock plate is perfectly straight and aligns with the edge of the door. Then, slowly screw the screws into the holes and attach the lock plate to the door again making sure to tighten the screws securely but don’t tighten them too much.
Step 5 - Test the Chain Lock
Take the chain hook or sliding cap and insert it into the lock plate on the door. Then, attempt to open the door. If the lock is installed correctly, the door should open only about an inch or so and the chain should prevent from opening father and the sliding cap should still remain at the bottom of the lock plate.