A mortise lock sits in a pocket cut into the door edge rather than through a bored hole, which gives it a far larger and stronger mechanism than a cylindrical lockset. It is the standard for serious commercial doors and it is what you find in almost every pre-war building in the GTA.
Typical range: $325–$1500 CAD. Ranges are typical for the GTA and depend on the door, the hardware and the time of day. We confirm the price before dispatching.
Why mortise locks are specified
The lock case can hold a latch, a deadbolt and the trim linkage together in one body anchored along the full depth of the door edge. That makes it substantially more resistant to forcing than a cylindrical lockset, and it allows function combinations — storeroom, classroom, office, entrance, dormitory — that a bored lock cannot easily provide.
The trade-off is the door prep. A mortise pocket is a significant cut, and converting a bored door to mortise means either a new door or a conversion kit. Going the other way, from mortise to bored, needs a filler plate and rarely looks right.
Heritage mortise locks
Toronto, Oakville, Aurora and Unionville all have substantial stock of pre-war doors with original mortise lock cases, and these are usually worth keeping. The cases were made to be serviced: they open up, the parts are steel, and a lock that has seized after eighty years is very often just dry and full of dust rather than broken.
Where a component genuinely has failed, the choice is fabricating a part or fitting a modern lock body behind the original trim. The second is usually the better outcome — original escutcheons and handles stay on the door, and the actual security becomes current. On heritage-designated properties this approach also avoids the permit issues that changing visible hardware can trigger.
Function options on commercial mortise locks
- Entrance / office — outside lever locked or unlocked by key or thumb-turn, inside always free
- Storeroom — outside lever always rigid, key retracts the latch, inside always free. The correct function for stock rooms and server rooms
- Classroom — outside lever locked and unlocked by key only, with no inside thumb-turn to be misused
- Passage and privacy functions for interior doors
- Electrified versions that fail safe or fail secure on power loss, for integration with access control
Frequently Asked Questions
Can an old mortise lock be repaired or does it need replacing?
Far more often than people expect, it can be repaired. Old lock cases were built to be opened and serviced, and the usual fault is accumulated dust and dried lubricant rather than a broken part. Cleaning, inspecting and relubricating a seized case frequently restores full function. Where a spring or a lever has actually failed, replacing the internal case while keeping the original trim is usually the sensible route.
What is the difference between a mortise lock and a regular lock?
A mortise lock sits in a rectangular pocket cut into the door edge; a cylindrical lockset goes through a round bored hole. The mortise pocket allows a much larger mechanism, so the lock is stronger, offers more function options, and can combine latch and deadbolt in one body. It also costs more and requires more door preparation.
My mortise lock handle droops. Is that serious?
It means the spring cage or the hub inside the case is worn, and it will progress to the handle failing to retract the latch at all. On a commercial door that becomes a lockout, and on an exit route it becomes a safety issue. It is repairable at the case level in most instances, and it is better addressed before it fails completely.
Can you fit a modern cylinder to an old mortise lock?
Usually yes. Most mortise cases take a standard threaded mortise cylinder, so a modern high-security cylinder on a restricted keyway can go straight into a century-old lock body. You keep the original appearance and get current key control, which on heritage properties is very often the ideal combination.
Mortise Locks across the GTA
We provide mortise lock repair & installation throughout the Greater Toronto Area. Pick your city for local detail, or call and we will tell you straight away whether you are in range.
Related services
High-Security Locks
Pick-, drill- and bump-resistant cylinders on patented restricted keyways, for doors where a standard cylinder is not adequate.
Commercial Door Repair
Doors that bind, drag, sag, will not latch or will not close — diagnosed at the door and frame rather than blamed on the lock.
Master Key Systems
Designed keying hierarchies — from a single master over a small office to multi-level grand master systems with restricted keyways and documented key control.
Lock Rekeying
Existing cylinders re-pinned to a new key — the fast, inexpensive answer to staff turnover, lost keys and taking over premises.