How Much Holding Force Do You Need for a Maglock Project?
Understanding Holding Force
Holding force is the measure of how strongly an electromagnetic lock can keep a door closed. In the UK and most of Europe, this value is usually expressed in kilograms, while in the USA and other regions it’s more commonly listed in pounds. But what does this number really represent—and how do you decide what’s suitable for your installation?
What Does Holding Force Mean?
An electromagnetic lock is made up of two components: the magnet (mounted to the frame) and an armature plate (fixed to the door). When energized, the magnet creates a magnetic field powerful enough to attract the armature plate and keep the door firmly shut.
Holding force—sometimes called pull strength—describes how much direct force (applied straight away from the magnet) would be needed to overcome that magnetic attraction.
It’s important to distinguish this from shear force, which refers to pressure applied sideways. Shear force doesn’t reflect the true pulling capacity of the lock and isn’t used when determining a maglock’s stated holding force.
Door size also plays a role. Larger or wider doors generate more leverage when pushed abruptly, which can momentarily exceed the stated holding force—especially if the door is struck or hit with a sudden impact.
What Holding Forces Are Available?
Electromagnetic locks are manufactured in a range of strengths. Most standard models fall between 180kg and 500kg, and many are available in both single and double configurations. Selecting the right strength is essential to maintaining proper security for the specific door and environment.
Choosing Holding Force for Internal Doors
Standard Internal Use
For interior doors used simply to control access—such as office doors or storage rooms—300kg of holding force is generally more than adequate. A person is unlikely to apply anywhere near that amount of force during normal use, making 300kg perfectly suitable for everyday internal applications.
High-Security Internal Doors
If the door protects sensitive areas, expensive assets, or restricted zones, you need to account for potential forced entry. A determined intruder could defeat a 300kg lock with effort, whereas 500kg offers substantially more resistance.
For maximum internal security, consider:
- A 500kg electromagnetic lock
- Double maglock assemblies
- Transom housings
These options significantly increase effective holding force.
Choosing Holding Force for External Doors
Exterior doors require careful consideration because their purpose varies:
When the Maglock Only Needs to Keep the Door Closed
If the electromagnetic lock is only there to hold the door shut during operating hours—while another lock provides actual security—then 300kg is usually sufficient.
When the Maglock Is the Primary Security Device
If the electromagnetic lock is the only mechanism securing the building when unoccupied, then 500kg should be treated as the minimum requirement.
Installers frequently overlook this distinction. A 300kg maglock is not strong enough to secure an external door against forced entry.
Why the Correct Holding Force Matters
Selecting the right strength is critical for safety and security. Underspecifying your holding force leaves the door vulnerable to physical attack, increasing the likelihood of unauthorised access.
When in doubt, opt for a higher rating—or contact a technical specialist for guidance.
