Taking Apart a Mortise Lock

What You'll Need
Vacuum or canned Air
Clean cloth
Silicone lubricant or graphite
Pencil and Paper
Label patches
Tiny soft brush

A mortise lock is a common type of locking device made up of a large rectangular body that fits into a pocket or mortise. The mortise is chiseled or carved into the edge of the door where the lock is installed. The mortise lock body contains the parts that actually make the lock work keeping the door secure. Inside the body are the workings for the knob or handle, latch, and deadbolt. Normally, a door frame of the door with a mortise lock will contain a solid metal plate that is level or flush with the frame. This plate is then secured in place with a set of screws. The plate has a pocket and the locking device of the mortise lock—normally a thick, steel bolt—slides into the opening when the key is turned, resulting in a securely locked door. This type of lock is durable, strong and heavy, but it will get rough or aged over time. Follow the steps below to take apart the mortise lock for refurbishment, cleaning or for replacement purposes. 

Step 1 – Examine and Clean the Installed Mortise Lock

Before you begin, clean the mortise lock to reveal all screws that are attaching the lock in place. After some time, metal locks may develop thick grime and dust. Examine the positions of screws and mechanisms keeping it in place. Turn the knob, and be aware of how the mechanism reacts to every moved part such as the result of turning the knob counterclockwise and clockwise.

Step 2 – Remove the Screws

Slacken off the setscrews on one of the doorknobs. After the screws are slackened, tug the knobs out slowly without destroying the setting of the doorknobs. Once the door knobs and the shaft are taken out, remove the two locks keeping locks in place. Remove the mortise lock slowly.

Step 3 – Place a Cloth

Put a clean cloth on the table. Lay the mortise lock on top of it. Unscrew the screws that bind the casing together. Remove the cover or housing of the lock.

Step 4 – Know the Parts Well

Look carefully at the parts and how they go together so you can put them back or replace damaged parts correctly.

Step 5 – Draw the Parts and Label

Take note of the different parts using a pencil and paper. Label each and one to remember exactly their location if incase you need to take some items out. Find inside the body the workings for the knob or handle, latch, and deadbolt. Make sure you understand clearly how each part contributes to the full working of the lock. Label the parts using small label patches.

Step 6 – Check & Repair Busted Parts

Become aware of any busted parts within the mortise lock. A busted part is usually a coil mechanism or a support or division that unites to the bolt of the lock. Take out the spring or the arm and find an alternate part to fix it. If you’re going to remove a part, put it in a safe place like a tool bowl and label them properly. Some parts might be too small and putting them just anywhere might lead to the misplacement of these tiny, possibly irreplaceable parts. Normally, if these parts are broken, it would be much easier to replace the entire unit. If the part is so small, use a scotch tape to keep it in place.

Step 7 – Clean the Mortise Lock

Clean the mortise lock by using a dry clean cloth, a tiny soft brush or canned air. Use a silicone lubricant or graphite on the mechanism to clean it. This is done by applying a mist of the lubricant on the lock.

Step 8 –Test and Install the Lock

Test the lock if all components are working. Mount the lock on the door and test if it’s working properly.