brief and clear
What is a mortise lock?
A mortise lock is a type of door lock that is embedded directly into the door leaf. It ensures secure locking and is installed invisibly inside the door, so it does not affect the appearance of the door. Mortise locks are especially common in residential buildings, office buildings, and public facilities.
Mortise locks are usually made of robust steel or brass to ensure durability and high resistance. When purchasing, pay attention to certified safety standards such as DIN standards or the VDS mark.
Advantages of a mortise lock
- High security: Installed in the door leaf, the lock is protected and difficult to tamper with.
- Visually unobtrusive: Doors remain visually appealing, as the lock is inside the door and the door surface stays smooth and elegant.
- Wide range of applications: Mortise locks are available for wooden, metal, and plastic doors.
- Various locking types: From simple cylinder locks to multi-point locking systems
- Easy retrofitting: Many models can also be retrofitted into already installed doors.
Types of mortise locks
- Buntbart mortise lock: Traditional and simple, often used for interior doors
- Profile cylinder mortise lock: Standard for front doors, compatible with cylinder locks
- Multi-point locking: Provides additional protection through multiple locking points
- Electronic mortise locks: Modern version with access via code, card, or app
Construction
The mortise lock explained briefly
Depending on the application, the mortise lock is a complex interplay of various components. Basically, there are three essential parts in a mortise lock: the follower, the latch, and the bolt.
follower
The follower is a central lock component. In panic locks, there is often a split follower with two halves that can rotate independently, each connected to the door handles via split spindle. This allows both handles to trigger different functions: inside, the door can be unlocked without a key; outside, the follower only operates the latch, and a key is required for the deadbolt.
In panic locks with a continuous follower, which can only be opened from the outside with a key, a fixed door knob is installed on the outside. Inside, the handle operates both the latch and the deadbolt via the follower.
follower
The follower is a central lock component. In panic locks, there is often a split follower with two halves that can rotate independently, each connected to the door handles via split spindle. This allows both handles to trigger different functions: inside, the door can be unlocked without a key; outside, the follower only operates the latch, and a key is required for the deadbolt.
In panic locks with a continuous follower, which can only be opened from the outside with a key, a fixed door knob is installed on the outside. Inside, the handle operates both the latch and the deadbolt via the follower.
latch
The latch, also known as the "latchbolt" or "spring latch", holds the door in the strike plate and is usually a beveled latch. When the door is closed, it is pushed against the spring into the strike plate and is retracted by operating the door handle, allowing the door to open.
Special types:
The so-called "silent latch" is equipped with a plastic cap and roller, which enables particularly quiet opening and closing of interior doors. Self-locking locks have a locking mechanism on the latch, so the door is locked even without locking it with the key – thus, insurance coverage is ensured even when the door is simply pulled shut.
latch
The latch, also known as the "latchbolt" or "spring latch", holds the door in the strike plate and is usually a beveled latch. When the door is closed, it is pushed against the spring into the strike plate and is retracted by operating the door handle, allowing the door to open.
Special types:
The so-called "silent latch" is equipped with a plastic cap and roller, which enables particularly quiet opening and closing of interior doors. Self-locking locks have a locking mechanism on the latch, so the door is locked even without locking it with the key – thus, insurance coverage is ensured even when the door is simply pulled shut.
deadbolt
A bolt in a door lock is a mechanical component that extends from the lock to provide additional security for the door. It engages in the recess of the door frame or the strike plate, thereby blocking the door from being pushed back. In contrast to the latch, which only holds the door closed, the bolt ensures that the door is also secured against forced opening. The bolt ensures that the door can only be opened with the appropriate key or by a specific operation, thus increasing the security of the door.
deadbolt
A bolt in a door lock is a mechanical component that extends from the lock to provide additional security for the door. It engages in the recess of the door frame or the strike plate, thereby blocking the door from being pushed back. In contrast to the latch, which only holds the door closed, the bolt ensures that the door is also secured against forced opening. The bolt ensures that the door can only be opened with the appropriate key or by a specific operation, thus increasing the security of the door.
The lock case – wooden/steel doors
The lock case on the left is a typical lock case for wooden or steel doors – recognizable by its significantly deeper design compared to a mortise lock for tubular frame doors (see illustration on the right).
The lock case is the housing of the mortise lock, in which the mechanism such as latch, bolt, and locking device are integrated. It is inserted into a specially prepared recess in the door and ensures the secure function of the lock. The lock case thus forms the central component of the mortise lock.
The lock case – tubular frame doors
The lock case is the housing of the mortise lock in which the mechanism such as latch, bolt, and locking device are integrated. It is inserted into a specially prepared recess in the door and ensures the secure function of the lock. The lock case thus forms the central component of the mortise lock. In general, a distinction is made between mortise locks for wooden and steel doors and for tubular frame doors.
A typical feature of mortise locks for tubular frame doors is the shallower lock case, as there is less space in aluminium profiles than in wooden or solid doors.
dummy-mullion
Definition and function:
The forend (also called "Stulpe") is the visible metal plate on the front of a lock and is an important component of a mortise lock. It is mounted on the narrow front edge of the door and is usually made of metal.
The forend has several functions:
Mounting: It is attached to the door with screws and ensures that the lock sits securely in the door.
Cut-outs: The forend has cut-outs for the latch and the bolt.
Visibility: After installation, the forend remains as a visible element on the door, while the other parts of the lock are concealed inside the door.
Dimensions and versions:
The dimensions of the forend are standardized, with typical dimensions for interior doors being a width of about 20 mm or 24 mm and a thickness of 3 mm. The ends of the forend can be square or rounded. The forend can also be made of various materials such as painted steel or stainless steel to match the door leaf.
dummy-mullion
Definition and function:
The forend (also called "Stulpe") is the visible metal plate on the front of a lock and is an important component of a mortise lock. It is mounted on the narrow front edge of the door and is usually made of metal.
The forend has several functions:
Mounting: It is attached to the door with screws and ensures that the lock sits securely in the door.
Cut-outs: The forend has cut-outs for the latch and the bolt.
Visibility: After installation, the forend remains as a visible element on the door, while the other parts of the lock are concealed inside the door.
Dimensions and versions:
The dimensions of the forend are standardized, with typical dimensions for interior doors being a width of about 20 mm or 24 mm and a thickness of 3 mm. The ends of the forend can be square or rounded. The forend can also be made of various materials such as painted steel or stainless steel to match the door leaf.
the keyhole
The keyhole is the opening in the lock case into which, for example, the profile cylinder is inserted. It is the interface between the profile cylinder and the locking mechanism in the lock case.
There are different types of keyholes. Typical keyhole types are:
1. Profile cylinder keyhole – for common profile cylinder locks, which are widely used today.
2. Bit key keyhole – an older, traditional keyhole for bit keys, often found in old or decorative locks.
3. Lever lock keyhole – similar to the bit key type, often found in antique locks.
4. Circular or round keyhole – a round keyhole, e.g. in padlocks.
5. Box lock keyhole – a larger, typical cut-out in box locks.
6. Combination lock keyhole – used with combination locks without a physical key.
The exact shape and size of the keyhole depends on the type of lock and the key profile used.
the keyhole
The keyhole is the opening in the lock case into which, for example, the profile cylinder is inserted. It is the interface between the profile cylinder and the locking mechanism in the lock case.
There are different types of keyholes. Typical keyhole types are:
1. Profile cylinder keyhole – for common profile cylinder locks, which are widely used today.
2. Bit key keyhole – an older, traditional keyhole for bit keys, often found in old or decorative locks.
3. Lever lock keyhole – similar to the bit key type, often found in antique locks.
4. Circular or round keyhole – a round keyhole, e.g. in padlocks.
5. Box lock keyhole – a larger, typical cut-out in box locks.
6. Combination lock keyhole – used with combination locks without a physical key.
The exact shape and size of the keyhole depends on the type of lock and the key profile used.
BKS mortise locks for every requirement
BKS offers a wide range of different mortise locks.
Your questions – our answers
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