Mortise Locks are built into a precisely cut pocket inside the door rather than mounted only on its surface. This construction combines the latch, deadbolt, follower and other operating parts within one metal case, creating a compact and stable locking system. Commonly specified for hotels, offices, hospitals, schools and apartment developments, Commercial Mortise Locks are valued for their security, replaceable components and ability to withstand frequent operation.
The lock case is installed inside the door edge and connected to handles, cylinders, thumbturns or access-control components. When the handle is operated, the follower retracts the latchbolt. Turning the key or thumbturn extends or retracts the deadbolt.
A typical assembly contains:
Lock case with internal springs and transmission parts
Latchbolt for normal door closing
Deadbolt for additional security
Forend and strike plate
Lever follower or spindle hub
Euro profile or other compatible cylinder
This recessed construction distributes operating forces through the door instead of relying entirely on surface-mounted fasteners.
Different mortise lock body types are designed around the required door function. A sash lock combines a latchbolt and deadbolt, while a deadlock operates without a latch. Bathroom models may include an occupancy indicator, and roller bolt locks are often selected for pull-handle doors.
| Lock body | Main function | Typical application |
|---|---|---|
| Sash lock | Latch and deadbolt | Offices and entrances |
| Deadlock | Deadbolt only | Storage and security doors |
| Latch lock | Latch only | Interior passage doors |
| Bathroom lock | Privacy and emergency release | Washrooms and changing rooms |
| Roller bolt lock | Holds door without lever operation | Commercial entrance doors |
Backset, center distance and door thickness must be confirmed before ordering. Common backsets include 50, 55, 60, 70 and 80 mm, while European commercial locks frequently use a 72 or 85 mm center distance. The forend profile must also match the door preparation, including square or radius corners.
Material selection affects durability. SUS304 components provide dependable corrosion resistance for most indoor and sheltered exterior installations. More exposed environments may require upgraded materials, finishes or corrosion testing.
Buyers should also review:
Applicable fire and mechanical standards
Tested operating cycle count
Latch and deadbolt projection
Cylinder and handle compatibility
Left-hand, right-hand or reversible operation
Wooden, metal or fire-door suitability
EN 12209 classifies mechanically operated locks according to use category, durability, door mass, fire suitability, safety, corrosion resistance and security. Fire-door installations may additionally require evidence under EN 1634.
D&D offers certified mortise lock configurations tested for up to 200,000 operating cycles, with selected products designed for wooden, metal and fire-rated doors. Certification should always cover the proposed lock configuration rather than an unrelated model from the same range.
A clear inquiry should include door material, thickness, opening direction, backset, center distance, cylinder type, handle design, finish, certification and required quantity. Providing door drawings or an approved hardware schedule helps prevent mismatched components.
Working with a qualified mortise lock wholesale supplier also makes it easier to coordinate samples, project finishes, keyed systems, packaging and replacement parts. Correct specification at the quotation stage reduces installation changes and supports consistent performance throughout the building’s service life.