An electromagnetic lock, magnetic lock or maglock is a locking device that consists of an electromagnet and an armature plate. There are two main types of electric locking devices:

Fail-Secure: This device remains locked when power is lost

Fail-Safe: This device will unlock when de-energised

Direct pull electromagnetic locks are inherently fail-safe. Typically the electromagnet portion of the lock is attached to the door frame, and a mating armature plate is attached to the door.

The two components are in contact when the door is closed. When the lock is energised, the current passing through the maglock creates a magnetic flux that causes the armature plate to attract the electromagnet, creating the locking action. Because the mating area of the electromagnet and armature is relatively large, the force created by the magnetic flux is strong enough to keep the door locked even under stress.

Single door electromagnetic locks are offered in both 600 and 1200 lbs dynamic holding force capacities. A "Fail-Safe" magnetic lock requires power to remain locked and are typically not suitable for high-security applications because it is possible to disable the lock by disrupting the power supply. Despite this, by adding a magnetic bond sensor to the lock and by using a power supply that includes a battery backup capability, some specialised higher security applications can be implemented. Electromagnetic locks are well suited for use on emergency exit doors that have fire safety applications because they have no moving parts and are therefore less likely to fail than other types of electric locks.

The strength of today's magnetic locks compare well with conventional door locks, and they cost less than conventional light bulbs to operate. There are additional pieces of release hardware installed in a typical electromagnetic locking system. Since electromagnetic locks do not interact with levers or doorknobs on a door, typically, a separate release button is pressed, keeps the lock unlocked for either 15 or 30 seconds in accordance with fire codes. Additionally, a second release is required; either a motion sensor or crash bar with an internal switch is used to unlock the door.

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