Electromagnetic Locks: Holding Force and Code Compliance
Electromagnetic locks (maglocks) hold doors shut with a powerful electromagnet bonded to the frame and an armature plate on the door. When power flows, attraction reaches hundreds to over a thousand pounds of holding force. Cut power and the door releases — making them inherently fail-safe unless paired with battery backup strategies.
Maglocks dominate glass doors and modern access-controlled entries where traditional strikes cannot fit. They also sit at the center of code debates: life-safety authorities require guaranteed egress, so maglock installations demand sensors, request-to-exit devices, and often fire alarm integration.
Fail-Safe vs. Fail-Secure
Maglocks are fail-safe: power loss unlocks the door. Electric strikes can be fail-secure (locked without power). Designers choose based on whether life safety or perimeter security takes priority during outages.
Holding Force Ratings
Common ratings include 600 lb and 1200 lb models. Glass doors and double doors may need dual maglocks. Holding force is not the same as kick resistance — proper alignment and armature mounting matter.
Code and Egress
IBC and NFPA require doors to unlatch without special knowledge during emergencies. Maglock permits often need fire alarm tie-in, PIR exit sensors, and crash bars on the egress side. Inspectors reject maglocks on exit doors without approved release pathways.
Power and Backup
Dedicated power supplies with battery backup keep maglocks engaged during brief outages — or release them, depending on system design. Fire alarm relays drop power to maglocks on alarm events to ensure evacuation routes open.
Locksmith and Integrator Role
Installing maglocks blends door hardware, low-voltage wiring, and access control software. Miswired REX sensors cause nuisance unlocks; undersized power supplies cause voltage drop and weak holding. See also access control for credential layers.