Concealed in door frame header
ANSI/BHMA A156.25 · UL 294
Maryland, DC & Northern Virginia
An electric drop bolt is a lock that sits inside the door frame header. When the system locks, a steel bolt drops into a strike plate on top of the door. When a user presents a card, code, or fob, the bolt pulls back up and the door swings open. Drop bolts work well on frameless glass doors, double-acting doors, and pairs of doors where other locks cannot easily mount. Most run on 12 or 24 VDC and connect easily to common access control systems.
The bolt hides inside the header, so glass storefronts keep a clean look without bulky boxes.
Pick fail-secure models that stay locked in a power outage, or fail-safe models for exit paths.
Drop bolts connect to card readers, keypads, and intercoms, so you control who enters and when.
King Locksmith And Doors Inc. is a commercial locksmith and door company based in Maryland. We install and service electric drop bolts for small businesses, government agencies, hospitals, hotels, and property managers across Maryland, Washington DC, and Northern Virginia. Our technicians handle the full job: frame prep, wiring, power supplies, and access control setup. We test every lock before we leave, so your door works on day one and stays secure for years to come.
The right electric drop bolt depends on your door, your power setup, and your local building codes. Use these five checks to narrow your choice before you buy a new lock or book an install.
Electric drop bolts suit frameless glass doors, aluminum storefronts, and double-acting doors that swing both ways. The bolt drops into a strike on the top rail, so the door needs a solid, flat top edge.
Glass doors without a metal top rail need a glass door strike kit or patch fitting instead. Wood and hollow metal doors work too, but an electric strike or mortise lock may suit them better. We can help you compare.
A fail-safe drop bolt unlocks as soon as power drops. Fire codes often require this mode on doors in an exit path, so people can leave quickly during an emergency.
A fail-secure drop bolt stays locked without power. It fits server rooms, pharmacies, and storage areas where security matters more. Many models switch modes with a simple jumper on the board. We help you pick the mode your local fire code allows on each door.
Most electric drop bolts run on 12 or 24 VDC. Check the current draw, then size the power supply so it can handle every lock on the circuit.
Wiring must reach the frame header through a door loop or concealed raceway. Add battery backup if the lock must keep working during short outages. A clean power supply also prevents chatter and early coil failure. We test voltage at the lock before we close the frame.
Many drop bolts include a built-in bolt position sensor. It tells your access control panel whether the bolt actually dropped into the strike, not just whether power reached the lock coil.
Pair it with a door position switch to catch doors left open or propped open by staff. Hospitals, pharmacies, banks, and government offices often need this audit trail for compliance. We wire both sensors and confirm the panel reports each state correctly during testing.
Look for electric drop bolts tested to ANSI/BHMA A156.25 and listed to UL 294 for access control units. These ratings show the lock has passed strict cycle, endurance, and safety tests.
Egress doors must also follow NFPA 101, the IBC, and your local building code. That may mean a request-to-exit sensor, a manual release button, or a fire alarm tie-in. Our team checks these needs during every site assessment and documents them for your records.
Electric drop bolts and magnetic locks both secure glass and access-controlled doors. Here is how they compare on power, looks, and real security, so you can pick the right lock.
Consideration
Electric Drop Bolt
Magnetic Lock
Can stay locked when power fails
Unlocks on power loss, leaving door open
Fail-secure models draw power only to unlock
Draws current constantly to stay locked
Mounts in header over frameless glass doors
Armature bracket often clutters clear glass doors
Bolt stays hidden inside frame header
Bulky magnet housing visible across door top
Steel bolt physically blocks door from opening
Holding force weakens with misalignment or dirt
Most drop bolt failures come from alignment, power, or wear. Spotting the signs early keeps your door secure and stops a small fault from turning into a costly building lockout.
We prep the frame header, mount the bolt and strike, and run wiring to your access panel.
We fix stuck bolts, failed solenoids, and worn strikes so your door locks and unlocks on command.
We correct door sag, pivot wear, and strike position so the bolt drops cleanly on every cycle.
We size power supplies, add battery backup, and run clean wiring that keeps your drop bolt reliable.
We connect drop bolts to card readers, keypads, intercoms, and fire alarm releases across your whole building.
We replace worn drop bolts or swap magnetic locks for drop bolts that fit your doors better.
Book a free site assessment today. We will recommend the right drop bolt, power setup, and wiring for your doors.
