A mag lock, short for magnetic lock or electromagnetic lock, is an electronic locking device that uses an electromagnet and a metal armature plate to secure a door. When electrical power is supplied, the electromagnet creates a magnetic field that holds the armature plate against it and keeps the door closed.
Mag locks are commonly used with access-control systems that use keycards, keypads, biometric readers, exit buttons, or other authorized credentials.
How Does a Mag Lock Work?
A typical mag lock has two main components: an electromagnet mounted to the door frame and an armature plate mounted to the door.
When the lock receives power, the electromagnet generates a magnetic field that attracts the armature plate. This creates the holding force that keeps the door secured.
When an authorized access signal is received, power to the electromagnet is interrupted and the magnetic connection releases, allowing the door to open.
Because the magnet needs continuous electrical power to remain locked, most conventional mag locks are designed as fail-safe devices. This means the lock releases when power is removed, which can support emergency egress when properly integrated with the building's life-safety system.
What Are Mag Locks for Doors Used For?
Mag locks for doors are primarily used where electronic access control is required. Common applications include:
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Office entrances
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Commercial buildings
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Retail stores
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Apartment and residential entryways
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Schools and educational facilities
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Healthcare facilities
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Industrial buildings
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Restricted-access rooms
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Interior security doors
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Building entrances and exits
They can be integrated with different access-control devices, including card readers, keypads, biometric readers, request-to-exit devices, and automatic door systems.
What Are the Main Parts of a Mag Lock?
A basic magnetic door lock consists of several components.
Electromagnet
The electromagnet is the powered portion of the lock. It is normally installed on the door frame and produces the magnetic field that holds the door closed.
Armature Plate
The armature plate is a metal plate attached to the door. When the electromagnet is energized, the plate is pulled tightly against it.
Power Supply
A continuous electrical supply is required to keep a standard mag lock energized. Access-control systems may also use backup power to maintain system operation during short power interruptions.
Access Control
A mag lock can be connected to an access-control system that determines when the lock should release. This can include a keypad, card reader, biometric reader, or other authorized control device.
Exit Device
A properly designed installation normally includes an appropriate means of authorized exit, such as an exit button or request-to-exit device, depending on the door and application.
Types of Mag Locks
Mag locks are available in different configurations for different door types and installation requirements.
Single-Door Mag Locks
Single-door magnetic locks are designed for individual doors and are commonly used for office and commercial access-control applications.
Double-Door Mag Locks
Double-door magnetic locks are designed for pairs of doors. They use multiple magnetic locking points within a configuration suitable for double-door openings.
Outdoor Mag Locks
Weather-resistant magnetic locks are designed for exterior applications such as gates and perimeter entrances. Outdoor installations require appropriate environmental protection and mounting hardware.
Shear Magnetic Locks
Shear locks use magnetic force differently from traditional surface-mounted mag locks and can be installed in applications where a more concealed appearance is required.
Specialized Mag Locks
Specialized models are available for applications such as glass doors, sliding doors, aluminum storefronts, and other non-standard openings.
How Strong Is a Mag Lock?
Mag locks are available with different holding-force ratings. Depending on the design, products can range from compact models to high-holding-force commercial locks.
For example, magnetic-lock products are commonly offered with holding forces around 600 lb and 1,200 lb, while specialized designs can provide higher ratings. The appropriate holding force depends on the door, installation, environment, and access-control requirements.
Holding-force ratings should not be treated as the only measure of a door's security. Correct installation, door construction, frame condition, access-control design, and life-safety requirements are also important.
Mag Lock vs. Electric Strike
Mag locks and electric strikes both provide electronic access control, but they secure a door in different ways.
|
Feature |
Mag Lock |
Electric Strike |
|
Main components |
Electromagnet and armature plate |
Electrically controlled strike |
|
Mounting |
Usually surface-mounted |
Installed in the door frame |
|
Locking method |
Magnetic attraction |
Controls the latch |
|
Power behavior |
Typically releases when power is removed |
Behavior depends on strike type |
|
Mechanical latch |
Not required for locking |
Works with the door's latch |
|
Common use |
Access-controlled doors |
Offices, commercial and residential doors |
A mag lock holds the door closed through electromagnetic force, while an electric strike changes the condition of the door's existing latch so authorized users can open it.
Are Mag Locks Secure?
A mag lock can provide strong electronic access control, but its security depends on the complete installation rather than the magnet alone.
Important factors include:
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Holding-force rating
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Door and frame construction
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Correct alignment
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Mounting hardware
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Access-control system
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Power supply and backup power
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Exit hardware
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Fire and life-safety integration
Because a conventional mag lock depends on continuous electrical power, removing power releases the lock. This characteristic makes proper system design particularly important for doors that must provide emergency egress.
What Happens to a Mag Lock During a Power Outage?
A conventional mag lock normally releases when electrical power is interrupted. This is one of the defining characteristics of electromagnetic locks.
The power-loss behavior is important for emergency exit routes. Mag locks should therefore be installed with the appropriate access-control, fire-alarm, exit, and life-safety components required for the particular building and jurisdiction.
Backup power can be used in some access-control systems to maintain operation during short power interruptions, but it does not change the fundamental fail-safe behavior of the electromagnetic lock itself.
Where Are Mag Locks Commonly Installed?
Mag locks are frequently found on doors where controlling and monitoring access electronically is more practical than relying on conventional keys.
Common locations include:
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Business entrances
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Office corridors
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Server and equipment rooms
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Apartment entrances
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School buildings
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Healthcare facilities
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Warehouses
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Industrial facilities
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Security-controlled interior rooms
They are especially useful when multiple users need access because credentials can be managed electronically rather than issuing and collecting physical keys.
Mag Lock vs. Traditional Door Lock
A traditional door lock generally uses a mechanical mechanism operated by a key, thumbturn, or other physical control.
A mag lock instead uses electromagnetic force and an electronic control system. This allows access to be managed through credentials such as keycards, PINs, or biometric identification.
Traditional locks can continue functioning without electricity, while conventional mag locks require electrical power to remain locked.
What Should You Consider When Choosing a Mag Lock?
Before selecting a magnetic door lock, consider:
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Door type and construction
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Single or double door configuration
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Interior or exterior installation
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Required holding force
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Access-control system
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Available power supply
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Backup power requirements
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Exit hardware
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Fire and life-safety requirements
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Mounting space
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Environmental conditions
The lock should be matched to the door and access-control system rather than selected solely by its advertised holding force.
Why Are Mag Locks Important?
Mag locks provide a way to combine physical door security with electronic access control. They can work with keycards, PINs, biometrics, sensors, and other access-control equipment, making them useful for buildings where access needs to be controlled or monitored.
Their relatively simple mechanical construction also makes them suitable for many high-traffic access points.
