How do Mortise Locks Work?

Mortise locks are a very popular old design that has stood the test of time. They are strong and reliable. They are also relatively diverse in their construction. Mortise locks are widely used in commercial spaces for their strength and reliability. Each model and brand will have slightly different components, but the mortise is designed to withstand use and abuse. Mortise locks are suitable for heavy use and are ideal for high-traffic businesses and buildings. The internal mechanism is also designed for easy replacement and maintenance. So how do mortise locks work? Read on for more information.

The Parts of the Mortise Lock

Handle/Knobs – The device that you will turn in order to retract the latch once the door is unlocked.

Strike Plate – This metal fixture is fastened onto the doorway to line up with the latch bolt and potential deadbolt that reside in the lock body of the mortise.

Lock Body – The housing for the bolt work, which are the components that will disengage and engage the lock.

Lock Cylinder – A threaded cylinder that will secure through the door into the lock body, so that when a key is inserted the door will unlock. A mortise lock cylinder will have a cam, which is a rotating rectangular piece of metal that manipulates the handle’s ability to retract the latch.

Through Spindle – This long rod that connects the handles/knobs through the door and mortise lock body.

Hard Collars – This is a metal protective ring that spins on the lock cylinder. By spinning freely, a pipe wrench (or other tool) cannot be used to pry out the cylinder.

Escutcheon Plates – Also known as rose plates, these fasten on either side of the door to create a sense of cohesion around the lock cylinder and handle

Day/Night Switch – This switch will lock the door from the outside and keep it unlocked on the inside, or engage to keep both sides unlocked.

Faceplate – The faceplate covers the internal systems of the lock’s housing parallel to the strike plate, but on the door itself. Sometimes the face plate on a mortise lock will be separate and other times it will be pre fitted to the lock body.

Working Principle of Mortise Locks

Mortise locks have a different internal function than the standard cylinder lock with drilling. The cylinder lock is more common on residential doors and can be easily identified by the lock cylinder installed inside the handle or knob. What is more difficult to see with the naked eye is that the locking bolt on these conventional locks is attached to the lock frame. And it's not as simple as a pre-assembled lock, which can also be used commercially. Pre-assembled locks are an assembly of several different parts that must be placed in a pocket (also called a mortise lock) of the door. The preassembled lock is also placed in a recess in the door, but an insert must be placed around the pocket.

If you look at the operation of the lock inside the lock case, you can see that the mechanisms are larger. And just by holding the parts in your hands, you can feel their weight. The size and weight allow the lock to withstand prolonged use. There will be two holes in the body of the lock. One is for the pin and the other is for the cylinder. These holes will be of different sizes (the larger hole is usually for the cylinder). The body is placed in a pocket cut into the door. The cylinder is then pulled into the lock body through the door, and the handles are threaded onto the spindle. The spindle must be mounted through the door and lock case before the handles are threaded. Turning the key in the cylinder turns the cam on the back of the cylinder and unlocks the lock. From there, the lever or handle will pull the lock back, or in some cases, the key must be used to retract the lock completely, and the lever will only be available to retract the unlocked lock.

With mortise locks' unique modular construction, locks can be taken apart and reassembled so that the history of some of these locks can be preserved. Their ability to do so also gives them a specific purpose. Once you understand the differences between mortise and tenon and other locks, you may find yourself feeling more secure. We are a mortise locks supplier, please feel free to contact us if you need them.