Terminology
Automatic Deadlatch
An automatic deadlatch is a locking mechanism that secures a door automatically when it closes, engaging the main bolt without requiring a key. This feature enhances security by ensuring that the door is always locked when shut, preventing unauthorised access. Commonly used in commercial and residential applications, it offers convenience as users don’t need to manually lock the door. The automatic deadlatch is especially useful for high-traffic doors, where manual locking is impractical. Typically, it includes a release mechanism that allows the door to open from the inside, facilitating safe and easy exit in case of emergencies.
Backset
The backset is a critical measurement in door hardware installation, referring to the horizontal distance between the front edge of the door (forend face) and the center of the keyhole or follower. Accurate backset measurement is essential for proper lock placement, as it affects both security and usability. Common backset distances are 44mm or 56mm in residential applications, though this can vary in commercial settings. Choosing the correct backset ensures that the lock aligns correctly with the door handle or knob, providing both comfort and ease of access when using the door.
Bathroom Lock
A bathroom lock is designed specifically for bathroom privacy, allowing the door to be secured from the inside while preventing external access. It typically includes a latch bolt operated by the handle and a deadbolt that is locked and unlocked with a thumb turn on the interior side. Unlike exterior locks, bathroom locks prioritise privacy over security, allowing easy exit without a key. Some bathroom locks also feature an emergency release slot on the exterior, enabling access if necessary. This type of lock provides a practical solution for privacy in bathrooms, bedrooms, and other interior spaces where discretion is needed.
Bolt
The bolt is a crucial part of a locking mechanism, extending into the door frame to secure the door when locked. There are various types of bolts, including deadbolts and latch bolts. Deadbolts, for instance, are solid and typically require a key or thumb turn to engage, providing enhanced security as they resist forced entry. When the lock is engaged, the bolt moves into a hole or strike plate on the frame, anchoring the door in place. The strength and design of the bolt are central to a lock's effectiveness, making it an essential feature for both door security and durability.
Centers
Centers refer to the vertical measurement between the center of the keyhole and the center of the follower hole on a sash lock. This measurement is crucial during lock installation, as it ensures the alignment of door hardware, such as handles or knobs, with the lock mechanism for smooth operation. Standard center measurements help installers match compatible hardware with the lock body. Inconsistent center measurements can lead to misalignment, making it difficult to operate the lock or compromising the door’s functionality. Centers play a significant role in the lock's usability, especially for sash and mortice locks.
Deadlatch
A deadlatch is a type of nightlatch or latch mechanism where the latch can be locked securely in place, preventing it from retracting without a key. Unlike a simple latch, the deadlatch provides extra security, as it cannot be “slipped” back open with a thin object or card. Deadlatches are commonly found on external doors, providing a layer of security against unauthorised entry while allowing easy egress from the inside. They’re often used in both residential and commercial doors due to their balance of convenience and security, combining ease of entry with effective locking capabilities.
Double Locking
Double locking is a security feature that deadlocks a latch lock door by turning the key in the opposite direction in the outside cylinder, adding protection against forced entry. With double locking engaged, the lock is immune to manipulation of the internal handle or "slipping" methods, where the latch could be pried open. This feature is common in many external door locks, including deadbolts and certain latch systems, and enhances security by making the lock harder to bypass. Double locking is widely used in residential and commercial buildings for its increased protection against unauthorised entry.
Escutcheon
An escutcheon is a protective plate or decorative cover that fits around a keyhole or cylinder. It shields the lock from dust and dirt and prevents damage to the surrounding door area, particularly when keys are frequently inserted. Escutcheons also enhance a door’s aesthetics, coming in various materials and finishes to match the door hardware. In addition to providing an attractive appearance, a security escutcheon can offer tampering protection by protecting the lock cylinder from attack. They are commonly found on both residential and commercial doors, combining style with functional protection.
Follower
The follower is the square hole within a lock mechanism that accepts a spindle bar, which is attached to the door handle or knob. When the handle or knob is turned, the spindle rotates within the follower, engaging the lock’s latch or bolt. The follower is central to the function of sash and mortice locks, as it transmits the motion from the handle to the internal locking mechanism. Made of durable materials to withstand wear, followers are integral to the lock’s operation, ensuring that turning the handle translates effectively to locking or unlocking the door. Common follower sizes are 8mm and 5mm in bathroom bolts.
Forend
The forend is the front face of a lock that is visible on the door edge and secured with screws. It is often made of metal and features a rectangular shape with screw holes and an opening for the latch or bolt. The forend plate provides stability to the lock and gives a finished look to the installation. Forend plates (face plates) are available in various finishes, complementing door aesthetics while providing reinforcement to the lock.
Keyed Alike
A keyed alike system allows multiple locks to be operated by a single key, providing convenience and reducing the need to carry multiple keys. For example, a front and back door could both be keyed alike, so one key can open both doors. Keyed alike systems are commonly used in residential and commercial settings where convenience is prioritised over the complexity of separate keys. However, it’s important to note that the security level remains the same as individual keyed locks, as the key only matches those locks explicitly configured for keyed alike functionality.
Keyed To Differ
Keyed-to-differ (individually keyed) - each lock is operated by its own unique key, and no other key should open it. This arrangement maximises security by ensuring that only specific keys operate specific locks. Keyed-to-differ locks are widely used in residential, commercial, and industrial settings where access needs to be controlled individually. However, due to a finite number of possible key combinations (or "differs"), identical keys might still appear in large installations, although the risk is minimal. Keyed-to-differ setups are ideal when access to certain areas needs to be restricted to designated individuals.
Latch
A latch is a spring-loaded bolt designed to hold a door in a closed position without locking it. Typically operated by the door’s handle or knob, the latch extends to catch onto a strike plate in the door frame, keeping the door shut. Latches are commonly used on internal doors and are not intended to provide significant security but rather to keep doors from opening inadvertently. Latch bolts can be retracted by turning the door handle, allowing easy access without the need for a key, making them convenient for everyday use.
Master Keyed
A master-keyed system allows each lock to be operated by its unique key, while a master key can open all locks in the system. This arrangement is frequently used in multi-occupancy buildings, such as apartments or office complexes, where tenants have individual keys but landlords or security personnel hold a master key. Master-keyed systems balance security and convenience, as each user has private access, yet designated personnel retain comprehensive control. This setup is ideal for situations where hierarchical access is necessary, enabling both individualised security and central management.
Mortice
A mortice is a recessed slot cut into wood to house a lock or other hardware. Mortice locks fit within these cutouts, allowing for a more secure and flush installation compared to surface-mounted (rim) locks. Mortice locks are widely used in both commercial and residential doors due to their strength and durability, as the lock body is secured within the door itself. Morticing requires precise cutting and installation, making it compatible with doors that demand a higher level of security and durability. Morticed installations also provide an aesthetically pleasing finish, with minimal protrusion from the door.
Nightlatch
A nightlatch is a type of lock that automatically engages a latch when the door closes. Available in mortice or rim lock formats, they can be operated with a key from the outside and a thumb turn or button from the inside. Nightlatches often have an internal button (snib) that can hold the latch in the extended or withdrawn position, giving users flexibility in securing the door. Widely used in residential properties, nightlatches provide a convenient locking solution, offering easy exit from the inside while ensuring the door locks upon closure from the outside.
Rebate
A rebate is a rectangular groove or recess cut into the edge of a piece of timber to receive a mating piece, creating a seamless fit between two components. In door hardware, a rebate is often cut into the meeting edge of double doors, allowing them to close flush without a gap. Rebates provide additional strength and stability in door installations, enhancing security by minimising gaps that could be pried open. They are commonly used in mortice locks on double doors, where rebated edges ensure a precise, secure alignment when the doors are shut. A rebate component (set) specific to the mortice lock to be installed must be used.
Rim Lock
A rim lock is a surface-mounted lock installed on the interior face of a door rather than being recessed into it. This type of lock includes a lock body and a latch that projects into a corresponding strike plate on the door frame. Rim locks are popular for their ease of installation and suitability for doors where morticing is impractical, such as thin or historically significant doors. Although rim locks may lack the flush appearance of mortice locks, they offer reliable security and are frequently used in older homes, sheds, and interior doors for functional and decorative purposes.
Shackle
The padlock shackle is the U-shaped or hinged metal bar on a padlock that passes through a hasp or other securing point. When the padlock is locked, the shackle secures the item by enclosing or latching onto it. Padlock shackles are commonly made of hardened steel to resist cutting or tampering. They come in different lengths and thicknesses, with extended shackles providing flexibility for securing thicker objects. The shackle is a critical component of padlock security, providing the locking mechanism that holds the padlock in place and secures items against unauthorised access or theft.
Snib
A snib is a small button or lever on the casing of a nightlatch or rim lock that allows the bolt to be held in either the extended (locked) or retracted (unlocked) position. By activating the snib, users can temporarily prevent the lock from automatically engaging when the door closes. This feature is convenient in homes or offices, where occupants might want quick re-entry without a key. Commonly found on rim nightlatches, the snib offers flexibility and added control over door locking, enabling users to bypass the automatic latching function when desired.
Throw
The “throw” of a lock refers to the distance a bolt or latch moves when it is operated by the key or handle. A longer throw offers increased security by providing a deeper engagement into the door frame, making it more challenging for forced entry attempts. Locks with extended throw distances are often rated as higher security because they offer more substantial engagement within the strike plate or frame. Measuring the throw is essential in door hardware selection, as it ensures the bolt extends adequately to secure the door, providing enhanced safety and durability.