Magnetic Locks: Complete Commercial Guide to Maglocks and Access Control

A magnetic lock is the access control hardware with the fewest moving parts and the most predictable failure mode of anything in the commercial door hardware category. There is no latch, no latchbolt, no cam, no cylinder, no tailpiece. The door is secured by a magnetic bond between an electromagnet mounted in the frame header and a steel armature plate mounted on the door. Power on, the bond holds. Power off, the bond releases instantly and the door swings freely. That simplicity is why magnetic locks appear on tens of thousands of commercial access control applications every year, from hospital corridor doors to university building entries to government facility perimeters. It is also why magnetic locks are misspecified and misinstalled more often than the specification guides acknowledge. Holding force selection, egress code compliance, armature plate alignment, outdoor corrosion factors, bond sensor wiring, and the request-to-exit configuration all produce field failures when any one of them is handled incorrectly. This guide covers every selection and installation variable, the outdoor armature corrosion failure that reduces rated holding force to a fraction of its specification without any visible sign, and the Securitron and Alarm Controls brands stocked at American Locksets since 2001.

What Is a Magnetic Lock and How Does It Work?

A magnetic lock, also called an electromagnetic lock or maglock, consists of two components: an electromagnet housing that mounts to the door frame header or face, and a steel armature plate that mounts to the door leaf. When the access control system energizes the electromagnet, it generates a magnetic field that bonds the electromagnet face to the armature plate face with a measured holding force, stated in pounds. When the system de-energizes the electromagnet, the field collapses instantly and the door is free to open.

The holding force is the amount of direct-pull force required to separate the electromagnet from the armature plate while the lock is energized. A 600-pound holding force lock requires 600 pounds of direct pulling force against the lock axis to break the bond. This is not the same as impact resistance or side-load resistance, which are lower than the rated holding force. The rated holding force applies only to direct perpendicular pull in the axis the lock is designed to resist.

Magnetic locks are inherently fail-safe devices. Power is required to maintain the locked state. When power is lost for any reason, including power failure, fire alarm activation, or access control system command, the bond releases. ANSI/BHMA A156.23 governs commercial electromagnetic locks, defining cyclical, dynamic, strength, and finish tests with Grade 1 requiring one million operating cycles. This fail-safe characteristic is required by life safety codes on any door serving a required means of egress, and it is also what makes magnetic locks categorically different from electric strikes, which can be configured fail-secure. A facility that needs a fail-secure locking device on a non-egress secured door needs an electric strike or electrified lockset, not a magnetic lock.

Direct Pull vs Shear Magnetic Locks

Two magnetic lock configurations cover the vast majority of commercial applications. The selection depends on the door swing direction and the architectural requirements for the opening.

Direct Pull Electromagnetic Locks

A direct pull magnetic lock mounts on the face of the door frame header, with the electromagnet face pointing downward and the armature plate mounting on the top face of the door leaf. When the door closes, the armature plate contacts the electromagnet face and the bond forms. The door is held closed by the vertical pull force of the magnetic bond. On inswinging doors, this configuration works without any bracket modification. On outswinging doors, an L-bracket or Z-bracket mounts the electromagnet to the pull side of the frame, angling it to make contact with the armature plate on the door face as the door swings to the closed position. Direct pull is the most common configuration for standard commercial hollow metal and aluminum frame doors in access control applications. Alarm Controls 600L, 600LB, 1200LB, and Securitron M32 and M62 Series are direct pull electromagnetic locks stocked at American Locksets in the magnetic locks section.

Shear Locks

A shear lock is a concealed electromagnetic lock where the electromagnet is mortised into the door frame header and the armature plate is recessed into the top of the door. When the door closes, the two components slide into contact in a shear plane rather than face-to-face contact. The holding force is applied in shear (parallel to the door face) rather than in direct pull (perpendicular). Shear locks are specified on glass doors, frameless glass entrances, and architectural applications where a surface-mounted maglock on the frame header would be visible and objectionable. Securitron SAM (Surface-Mounted Shear Lock) and concealed shear configurations cover this application at American Locksets. The trade-off for the concealed installation is higher cost and more complex installation, including precise door prep and frame mortising.

Configuration	Mounting	Best Application	Key Models
Direct Pull	Surface, frame header	Standard hollow metal and aluminum doors	Alarm Controls 600L/1200LB, Securitron M32/M62
Direct Pull Outswing	L-bracket or Z-bracket	Outswinging commercial doors	Alarm Controls 600L + AM6370C bracket
Shear Lock	Concealed in header	Glass doors, architectural frames	Securitron SAM Series
Double Door	Dual electromagnet or split armature	Paired doors without center mullion	Alarm Controls 1200D, Securitron DM62

Holding Force: 600 lb vs 1200 lb vs 1500 lb

Holding force is the specification variable that gets over-engineered most consistently on commercial maglock projects. The assumption that more holding force means more security is incorrect in most applications and leads to unnecessary cost and, in some cases, egress problems when the release system is sized for a lower-force lock than what was installed.

600-Pound Holding Force

A 600-pound magnetic lock is the correct specification for interior doors, interior tenant entry doors, storage room doors, office corridor doors, and any access-controlled interior opening where forced-entry resistance is not the primary concern. 600 pounds of holding force is far more than any single person or two people can overcome by pulling on a standard door handle. The force to open any door using a handle is mechanically limited by the lever arm of the handle and the structural capacity of the door panel itself. A 600-pound maglock on an interior office door provides more than adequate security for the application. Alarm Controls 600L and Securitron M32 Series cover 600-pound single-door applications. Alarm Controls 600DLB and Securitron DM62 cover 600-pound double-door configurations.

1200-Pound Holding Force

A 1200-pound magnetic lock is the standard specification for exterior perimeter doors, building main entries, stairwell doors, and any door where forced-entry resistance is a genuine design requirement. The 1200-pound rating is also specified when wind load or other environmental forces act on the door panel in a way that could reduce the effective holding force of a lighter lock. Alarm Controls 1200LB (with bond sensor and door status) and Securitron M62 and VM1200 Series cover 1200-pound single-door applications. Alarm Controls 1200D covers double-door configurations at 1200 pounds per leaf. All are in the Alarm Controls maglocks catalog at American Locksets.

When 1500 Pounds Is Required

A 1500-pound or higher specification is reserved for high-security applications: government facilities with forced-entry specifications, detention and correctional applications, data centers, and oversized doors or gates where the door panel area creates higher wind load forces that act against the magnetic bond. The Securitron M82B Series is rated for challenging indoor and outdoor high-security environments and covers applications where standard 1200-pound locks are insufficient. For standard commercial office, healthcare, educational, and institutional applications, 1500-pound locks are an overspecification that adds cost without meaningful security benefit.

Egress Code Requirements: NFPA 101 and IBC

Magnetic locks on required means of egress are subject to specific release requirements under NFPA 101 and IBC. The fail-safe nature of magnetic locks makes them generally permissible on egress doors, but the method of release and the monitoring requirements depend on the occupancy type and the door's position in the egress path.

The Three Required Release Methods Under NFPA 101

NFPA 101 Section 13.2.1.6.2 requires that magnetic locks on egress doors in assembly occupancies (and under IBC Section 1010.1.9.9 for all applicable occupancies) must release by all three of the following simultaneously: activation of the building fire alarm system, loss of power to the lock, and a request-to-exit device located on the egress side of the door within 5 feet of the door, visible and accessible from the secured side. The fire alarm integration requirement means every magnetic lock installation on an egress door must be wired through the fire alarm panel or a fire alarm relay so the lock releases automatically when the alarm activates. This is not optional and is verified on every fire door inspection and commercial occupancy inspection.

The request-to-exit (REX) device is a pushbutton, motion sensor, or touchless infrared sensor that releases the magnetic lock when a person approaches or presses it from the egress side. On doors that also carry panic exit devices, the exit device push bar activation can serve as the REX signal, eliminating the need for a separate REX button if the wiring integrates the exit device signal with the maglock power circuit.

One critical wiring detail: the REX button must be wired to directly interrupt power to the magnetic lock, not to send a signal to the access control panel that then commands the lock to release. A REX wired through the access control CPU introduces a software-dependent delay in the release sequence. If the access control system is offline, rebooting, or experiencing a software fault, the REX may fail to release the lock. This is a code violation and a life safety failure. The REX must interrupt lock power directly, bypassing the access control panel entirely.

Magnetic Locks on Fire-Rated Doors

Magnetic locks on fire-rated door assemblies must carry a UL listing for fire door use, be fail-safe, and release on fire alarm activation. NFPA 80 requires all hardware on fire-rated assemblies to be listed for the rating. Additionally, magnetic locks must not hold a fire-rated door open. If a maglock is specified as a hold-open device on a fire-rated door, the fire alarm integration must be verified to release the lock and allow the door to close under its commercial door closer when the alarm activates. Testing this release sequence after installation is required before the assembly passes fire door inspection.

The Outdoor Armature Plate Corrosion Failure Nobody Measures

This is the magnetic lock failure mode that generates the most misdiagnosed service calls on exterior commercial installations, and it is the one detail absent from virtually every magnetic lock specification guide.

A magnetic lock's rated holding force depends entirely on the full surface-to-surface contact between the electromagnet face and the armature plate face. The armature plate on most commercial magnetic locks is mild steel with a plated finish, typically nickel or chrome. In coastal, high-humidity, or outdoor environments, the plated surface of the armature plate oxidizes over time. The oxidation layer is not visible from more than a few inches away. It does not look like rust. It looks like a slight darkening or matte finish on what was a polished plate. But the oxidation layer is non-magnetic. It acts as a physical spacer between the plate and the electromagnet face, creating a microscopic air gap that dramatically reduces the effective magnetic contact area.

On a 1200-pound magnetic lock with an oxidized armature plate, the actual holding force can drop to 400 to 600 pounds without any electrical fault, without any visible misalignment, and without any alarm from the access control system. The bond sensor on the lock may still report "secured" because the plate is physically touching the electromagnet. What the bond sensor detects is physical contact, not holding force. The lock appears fully operational until someone applies a modest force to the door and it gives way.

The field test is simple and is not performed often enough: use a calibrated pull-force gauge on the armature plate while the lock is energized. Any reading below 80 percent of the rated holding force on a lock that is less than three years old in a non-coastal environment, or any exterior lock regardless of age, should trigger armature plate inspection and cleaning. Clean the armature plate and electromagnet face with a non-abrasive cloth and a mild non-corrosive cleaner before checking force again. If the force does not recover after cleaning, the armature plate has oxidized beyond the point where surface cleaning restores contact area and the plate must be replaced. Securitron and Alarm Controls both stock replacement armature plates separately, which is the correct solution rather than replacing the entire lock. American Locksets stocks replacement armature plates for Securitron and Alarm Controls maglocks. Call 877-471-4870 to confirm the correct replacement armature part number for any existing lock model before ordering.

Bond Sensors and Door Position Switches: Why They Matter

A bond sensor (also called a security condition sensor or SCS) monitors the quality of the magnetic bond between the electromagnet and the armature plate. When the bond is complete and the holding force is within specification, the bond sensor outputs a "secured" signal to the access control panel. When the bond is interrupted, whether because the door opened, the armature plate is misaligned, or an object is between the plate and the magnet, the sensor outputs an "unsecured" signal.

Bond sensors detect physical separation at thresholds as low as 0.007 inches (0.18 mm). This sensitivity means a bond sensor correctly identifies when a door is not fully closed and the magnetic bond is not complete, which is the most common cause of "door held open" alarm conditions. Alarm Controls 600LB, 1200LB, and the 600DLB double-door model all include bond sensors as standard. Securitron M-series with the "B" suffix (M32B, M62B) includes both bond sensor and door position switch outputs.

A door position switch (DPS) is a separate reed switch sensor that detects whether the door leaf is physically in the closed position, regardless of whether the magnetic bond is complete. This distinction matters: a bond sensor reports on the maglock bond quality, while a door position switch reports on the door's physical position. Both outputs provide the access control panel with status information that a single sensor cannot provide alone. A door that is physically closed but has a misaligned armature plate will register "unsecured" on the bond sensor but "closed" on the DPS, pointing directly to an alignment or armature plate issue. A door that is physically open will register "open" on both. The Securitron M32D and VM1200DB include door position switch output alongside bond sensor for full dual monitoring.

Securitron Magnalock Series at American Locksets

Securitron, an ASSA ABLOY brand, manufactures the Magnalock Series, which has been the institutional specification standard for commercial electromagnetic locks for decades. The Magnalock line covers 600-pound and 1200-pound holding forces across direct-mount, bracket-mount, indoor, and indoor/outdoor configurations. The Securitron M32 Series provides 600-pound holding force for indoor/outdoor traffic control applications including door position switch variants. The M62 Series provides 1200-pound holding force for higher-security indoor and outdoor applications. The M82B Series is rated for challenging outdoor high-security environments requiring maximum holding force and environmental resistance.

The Securitron VM1200 and VM600 Vista Series are value-priced alternatives to the M-Series that retrofit the same competitive footprint, allowing replacement of competitive brand maglocks without frame or door modification. The VM1200DB and V2M600DB include dual-voltage input (12/24VDC selectable) with bond sensor and door position switch, covering the most common retrofit and new-installation specifications in a single catalog number. The complete Securitron Magnalock range including the M32, M34, M38, M62, M68, M82B, DM62 double-magnet series, MCL cabinet locks, and SAM shear locks is in the Securitron maglocks section at American Locksets.

Alarm Controls Electromagnetic Locks at American Locksets

Alarm Controls produces a full electromagnetic lock line covering 600-pound and 1200-pound single and double-door configurations with optional bond sensor, door status, and LED status indicator outputs. The 600L is the base single-door 600-pound lock with LED status indicator. The 600LB adds bond sensor and door status sensor outputs. The 1200LB is the 1200-pound single-door version with full bond and door status monitoring. The 600DLB is the double-door 600-pound configuration with bond and door status. The 1200D covers double-door applications at 1200 pounds per leaf.

Alarm Controls also stocks the 600WP weather-resistant magnetic gate lock at 600 pounds for outdoor gate applications where a standard interior-rated lock would corrode. For projects requiring dark bronze finish to match architectural hardware schedules, the 600DDURO and 600DLBDURO provide double-door 600-pound configurations in dark bronze anodized finish. Mounting accessories including the AM6300 spacer plate for 1200-pound locks, AM6332 half-inch spacer, and AM6370C Z-bracket with dress cover for outswinging single-door applications complete the Alarm Controls range. The full Alarm Controls electromagnetic lock catalog is in the Alarm Controls electromagnetic locks catalog at American Locksets.

Why Choose American Locksets for Magnetic Locks

American Locksets has been an authorized commercial hardware distributor since 2001, stocking electromagnetic locks from Securitron and Alarm Controls across every holding force, door configuration, monitoring output, finish, and outdoor rating in the product lines. Every magnetic lock order is confirmed for holding force, door swing, mounting configuration, voltage, bond sensor requirement, and fire alarm integration method before shipping. Same-day shipping is available on stocked configurations.

Magnetic locks at American Locksets ship alongside keypad and proximity locks for credential-reader applications, Adams Rite electric strikes for fail-secure and latch-based access control alternatives, exit devices and panic hardware for coordinated egress hardware schedules, commercial mortise locks for full-function entry sets, and builders hardware on a single authorized dealer order. For help confirming holding force, mounting configuration, code compliance, bond sensor wiring, or replacement armature plate part numbers for a specific project or existing installation, call 877-471-4870 before ordering.

Frequently Asked Questions About Magnetic Locks

What is the difference between a 600-pound and 1200-pound magnetic lock?

The holding force rating is the amount of direct perpendicular pull required to break the magnetic bond. A 600-pound lock is correct for interior office doors, tenant entry doors, storage rooms, and interior access-controlled openings where forced-entry resistance is not the primary concern. A 1200-pound lock is the standard for exterior perimeter doors, building main entries, and stairwell doors where forced-entry resistance and wind load on the door panel are design factors. Overspecifying 1200 pounds on an interior office door adds cost without meaningful security benefit.

Are magnetic locks fail safe or fail secure?

Magnetic locks are inherently fail safe. They require continuous power to maintain the locked state. When power is removed for any reason, including power failure, fire alarm activation, or access control system command, the magnetic bond releases instantly and the door swings freely. There is no fail-secure configuration for a magnetic lock. If a fail-secure locking device is required on a non-egress secured door, an electric strike or electrified lockset must be specified instead.

What is a request-to-exit (REX) device and is it required?

A request-to-exit device is a pushbutton, motion sensor, or infrared sensor on the egress side of a magnetically locked door that releases the lock when activated, allowing exit without credentials. NFPA 101 and IBC require a REX device on any magnetic lock installed on a required means of egress door. The REX must be wired to directly interrupt power to the magnetic lock, not through the access control panel CPU. Wiring the REX through the access control system introduces a software-dependent delay that fails code compliance and creates a life safety risk if the system is offline.

Can magnetic locks be used on fire-rated doors?

Yes, if the lock carries a UL listing for the specific fire rating of the assembly. The lock must be fail safe, must release on fire alarm activation, and must not hold the door open without proper fire alarm integration. The fire alarm release must be tested after installation to confirm the door closes fully under its rated door closer when the alarm activates. Magnetic locks on fire-rated assemblies are also subject to NFPA 80 hardware listing requirements in addition to NFPA 101 egress requirements.

What is a bond sensor on a magnetic lock?

A bond sensor monitors the quality of the magnetic contact between the electromagnet and armature plate. When contact is complete and the holding force is within specification, the sensor outputs a "secured" signal to the access control panel. When contact is interrupted or degraded, it outputs an "unsecured" signal. Bond sensors detect separation at thresholds as low as 0.007 inches. Alarm Controls 600LB, 1200LB, and 600DLB, and Securitron M-series "B" suffix models include bond sensors as standard. A door position switch (DPS) is a separate sensor reporting the door's physical position independent of bond quality.

Why would my magnetic lock lose holding force without any visible problem?

The most common cause is armature plate oxidation on exterior or high-humidity installations. The armature plate's plated steel surface develops a non-magnetic oxidation layer that creates a microscopic air gap between the plate and the electromagnet face, reducing effective contact area and dropping actual holding force significantly below the rated specification. The bond sensor may still report "secured" because it detects physical contact, not force. Test holding force with a calibrated pull-force gauge periodically. Clean the armature plate and electromagnet face with a non-abrasive cloth. If force does not recover after cleaning, replace the armature plate rather than the entire lock.

Which magnetic lock brands does American Locksets carry?

American Locksets stocks electromagnetic locks from Securitron (M32, M34, M38, M62, M68, M82B Series, DM62 double-magnet, MCL cabinet locks, SAM shear locks, VM1200 and VM600 Vista Series) and Alarm Controls (600L, 600LB, 600DLB, 1200D, 1200LB, 600WP weather-resistant gate lock, and dark bronze DURO finish variants) with full mounting accessory lines including spacer plates and Z-brackets. Same-day shipping on stocked configurations in the magnetic locks section at American Locksets with specification support at 877-471-4870.