Magnetic locks and electric strikes are electrical hardware devices used to maintain the security of a door opening. Both of these devices can be activated by a range of tools, including passcodes, biometric readers, keycards or buzzers. When comparing magnetic locks to electric strikes, consider factors such as intended function, security needs, safety egress and cost to help you choose between the two.
A magnetic lock, or mag lock, consists of a large magnet that is installed along the top of a door frame. A metal plate, or armature plate, is fastened to the door so it lines up with the magnet. When electrical power is supplied to the magnet, it creates a magnetic charge that keeps the magnet tightly pressed to the metal plate. This keeps the door securely locked until power is removed or interrupted.
An electric strike must be used along with some other form of locking device, such as a lockset or exit device (panic bar). Electrical power is supplied to the strike, which holds the lock bolt in place, keeping the door locked until the strike is activated by a buzzer, keycard or other device.
With a magnetic lock, the door is always locked from both sides of the opening. This makes mag locks a very secure option for areas that require high levels of security. Users must activate the lock with a keycard or other device when leaving and when entering. A handle or latchset is used to operate the door, but typically has no locking function.
Electric strikes provide security only for the exterior side of the door. Occupants can freely exit at anytime from inside the building simply by turning the knob or handle, or by depressing the pad on the exit device. From the outside, the door can only be unlocked with a keycard or other activating device, which signals the strike to release the lock bolt.
All electrical hardware can be described as either "fail-safe" or "fail-secure." Fail-safe hardware stays locked when power to the hardware is cut, keeping the building secure. Fail-secure hardware unlocks once power is cut, allowing for safe egress of occupants. A magnetic lock is always fail-safe, and unlocks automatically if power is cut. Electric strikes can typically be set to either of these two options using an integral switch. All fire-rated doors must be equipped with fail-safe hardware for safe egress at all times.
Because a magnetic lock is installed on the face of the door and frame, it can be installed relatively easily by most contractors. It is one of the most effective types of hardware for securing both sides of a door, and provides a great door of force to keep the door secure.
Electric strikes are usually more affordable than magnetic locks, making them a good choice for building managers on a budget. It is also easier in general to meet fire and life safety codes with an electric strike than with a mag lock. An electric strike is much less likely to delay egress because it can be easily operated from the inside of the building.
Magnetic locks are among the more expensive types of door hardware. They are also fairly easy for burglars to beat, because they will no longer keep the door locked if the power is cut. Finally, these locks pose a potential safety hazard in terms of slowing egress during an emergency.
Because of the complexity of powering and installing electric strikes, they typically require skilled installers. These strikes must be chosen carefully based on the type of lock they will be used with. If the wrong strike is chosen, the lock bolt won't fit securely inside.