ANSI/BHMA A156.31: Electric Strikes

Q: What maintenance does an electric strike require?

Electric strikes are low maintenance. Test monthly by triggering from the access control system. Check wiring connections annually. On fire-rated doors, include in the annual NFPA 80 fire door inspection. Replace any strike with sluggish operation.

Grading, wiring, and fire rating requirements for commercial electric strikes

By US Made Supply

Updated October 17, 2026

How we write and check our guides

Overview BHMA Grading Fail-Safe vs Fail-Secure Voltage and Wiring Fire Rating Compatibility Compatible Locksets Selection Guide FAQ Products Related Resources

What is ANSI/BHMA A156.31?

ANSI/BHMA A156.31 is the performance standard for electric strikes and frame-mounted electric actuators. It covers the hardware that lets you remotely release a locked door without changing the lock itself. When someone buzzes you into an office lobby or badges into a hospital wing, an electric strike is doing the work.

The standard is maintained by the Builders Hardware Manufacturers Association (BHMA) and sets requirements for durability, strength, and operational performance. It applies to strikes used with cylindrical locksets, mortise locksets, and rim-mounted exit devices.

If you are specifying access control hardware for a commercial building, A156.31 grading tells you how long the strike will last and how much abuse it can take. Building codes and spec writers reference this standard to set minimum requirements for schools, hospitals, offices, and other occupied buildings.

BHMA Grading: Grade 1 vs Grade 2

A156.31 defines performance grades based on cycle testing and dynamic strength. Grade 1 is the top tier. Most commercial specs call for Grade 1, and manufacturers like Von Duprin and HES build the majority of their product lines to that level.

Requirement	Grade 1	Grade 2
Cycle testing	1,000,000 cycles	500,000 cycles
Dynamic strength	70 ft-lbs	50 ft-lbs
Typical use	High-traffic commercial, institutional	Light commercial, interior doors
Fire-rated openings	Set by the listing, not the grade	Set by the listing, not the grade

Cycle testing simulates years of daily use. At 100 operations per day, a Grade 1 strike rated for 1,000,000 cycles would last roughly 27 years before the mechanism wears out. Grade 2 at 500,000 cycles gives you about 13 years at the same rate.

Dynamic strength measures how much impact force the strike can absorb while staying functional. The 70 ft-lb Grade 1 rating accounts for someone slamming a heavy commercial door or applying force during an emergency. Grade 2 at 50 ft-lbs handles normal commercial traffic but is not suited for high-abuse locations like stairwells or emergency exits.

Tip: When a spec says "BHMA Grade 1 electric strike," it means A156.31 Grade 1 specifically. Do not confuse this with the A156.4 grading for door closers or A156.3 grading for exit devices. Each standard has its own grade definitions and test criteria.

Fail-Safe vs Fail-Secure

Every electric strike operates in one of two modes. Picking the wrong one can create a life-safety problem or a security gap. This is the single most important decision when specifying an electric strike.

Fail-Safe (Fail-Unlocked)

The strike stays locked when power is applied and unlocks when power is cut. During a power outage, the door can be opened from the outside.

Not fire rated: never use one on a fire-rated door, which must stay positively latched
Suits non-rated doors where losing power should release entry from the outside
Egress does not depend on it: with the usual lock and exit device functions, the door still opens from the inside
Not the way to provide stairwell re-entry: where the code requires it, re-entry is usually done with fail-safe electrified locks or exit device trim, so the door still latches

Fail-Secure (Fail-Locked)

The strike stays locked when power is cut and unlocks when power is applied. During a power outage, the door remains locked from the outside. The lever or knob on the inside still allows free egress mechanically.

Maintains security during power loss
Common on perimeter doors, server rooms, and restricted areas
Mechanical free egress from inside is still required by code
The mode for fire-rated doors: manufacturers list their strikes for fire doors in fail-secure only

Warning: Never install a fail-safe strike on a fire-rated door. It releases the latch whenever power is removed, by an outage or by a control sequence that cuts power on a fire alarm, so the door would no longer stay latched closed. NFPA 80 requires fire doors to be positively latched. On a rated opening, specify a fail-secure strike listed for the door's rating (Von Duprin calls this FSE; FS, fail-safe, is not fire rated).

Voltage and Wiring

Electric strikes typically run on low-voltage DC power. The two most common options are 12V DC and 24V DC. Some models accept a range (12-24V AC/DC), but DC is preferred for new installations because it allows the use of battery backup.

Specification	12V DC	24V DC
Typical inrush current	300-600 mA	150-300 mA
Typical holding current	150-250 mA	75-125 mA
Max wire run (18 AWG)	~200 ft	~400 ft
Common power supply	1A @ 12V DC	1A @ 24V DC
Battery backup	12V sealed lead-acid	24V sealed lead-acid

Power Supply Sizing

Size your power supply for inrush current, not holding current. If you are running multiple strikes off one supply, add up the inrush current of all strikes that could fire simultaneously. A good rule of thumb: use a power supply rated at 150% of your calculated peak draw.

Tip: Use 24V DC for long wire runs. Voltage drop over distance is the most common cause of electric strike issues in the field. At 200+ feet, a 12V system may not deliver enough voltage to reliably actuate the strike. Check the manufacturer's voltage drop tables before finalizing your wire gauge and run length.

Fire Rating Compatibility

An electric strike installed on a fire-rated door must not compromise the opening's fire rating. The strike must be listed for fire door use (fire door hardware is tested under UL 10C, the positive pressure fire test), and the finished opening must stay within the listing and configuration limits of every component in it.

Listed for the opening: Check the strike's maximum listed rating and its exact listed configuration (single door or pair, mullion, latch type, fail-secure) against the opening. A strike can carry a longer rating on a single door than on a pair
Components listed separately: The door, frame and strike can each carry their own listing. Together they must stay within every listing's configuration limits and the manufacturers' instructions
Fail-secure required: A fire door must close and stay latched during a fire, so only fail-secure strikes carry fire listings. Fail-safe strikes are not fire rated
Hold-open is a separate device: An electric strike only releases the latch. Anything that holds a fire door open must release on the required alarm or power-loss signal so the door closes and latches
NFPA 80 inspection: Electric strikes on fire-rated doors are part of the fire door inspection NFPA 80 requires, annually by default (an AHJ can accept a written performance-based program instead)

A door's required fire rating comes from the wall or barrier it sits in (IBC Table 716.1(2) and your local amendments), not from the room name. Whatever the rating, the electric strike must be fail-secure and listed for that rating and that configuration of opening.

Warning: An unlisted or incompatible strike on a fire-rated door, or a labeled frame modified without approval, leaves the opening out of compliance with its fire listing. Each component and each field preparation must be allowed by its listing and the manufacturer's instructions. Check the manufacturer's fire listing documentation before installation. A fire door inspection or the AHJ can flag it.

Compatible Locksets

Electric strikes work by releasing the latchbolt, so the strike must match the type of lock installed on the door. Using the wrong strike for your lockset type is a common mistake that leads to callbacks.

Cylindrical Locksets

Standard lever or knob locks with a spring-loaded latchbolt (typically 1/2" to 5/8" throw). These are the most common locks in commercial buildings and have the widest selection of compatible electric strikes.

Most electric strikes are designed for cylindrical locksets
Latch throw of 1/2" to 5/8" is standard
Strike must accommodate the latch lip geometry
Works with brands like Schlage, Sargent, and Yale

Mortise Locksets

Heavier-duty locks with a full mortise body recessed into the door edge. Mortise locks have a longer latchbolt throw (up to 3/4") and a separate deadbolt. The electric strike only releases the latchbolt, not the deadbolt.

Requires a strike rated for 3/4" throw latchbolts
Deadbolt must be retracted separately (usually by thumbturn or key)
Common in institutional and high-security applications
Brands include Sargent, Corbin Russwin, and BEST

Rim Exit Devices

Panic bars and exit devices mount on the door surface and use a Pullman-type latchbolt. Electric strikes for rim exit devices are larger and heavier-duty than standard strikes.

Requires a strike specifically designed for rim exit device latch geometry
Must handle higher forces from panic hardware
Often Grade 1 rated for code compliance on exit paths
Compatible with Von Duprin, Sargent, and Precision exit devices

Tip: Always verify compatibility with the specific lock model, not just the lock type. Faceplate dimensions, latch projection, and lip length vary between manufacturers. Most electric strike manufacturers publish compatibility charts for major lock brands.

Selection Guide by Application

Use this table to narrow your search based on the building type and door function. These are starting points. Whether a door is fire rated depends on the wall it sits in, not the room name, so check the opening's label. Always confirm the final spec with your architect or security consultant.

Application	Grade	Mode	Notes
School classroom	Grade 1	Fail-secure	Lockdown needs often decide the mode
Hospital patient wing	Grade 1	Fail-secure if the door is rated	High cycle count, quiet operation
Office suite entry	Grade 1 or 2	Fail-secure	Card reader or intercom release
Retail stockroom	Grade 2	Fail-secure	Lower traffic, security priority
Stairwell / exit door	Grade 1	Fail-secure	Must work with the exit device. Where the adopted code requires re-entry, it is usually met with fail-safe electrified locks or exit device trim while the strike stays fail-secure
Server room	Grade 1	Fail-secure	Audit trail from access control
Apartment lobby	Grade 1	Fail-secure if the door is rated	Intercom or video release

Grade 1 is a common specification for high-use openings and exit paths. On any fire-rated door the strike must also be fail-secure and listed for the rating, which is a listing requirement separate from the grade.

Frequently Asked Questions

Can I replace a mechanical strike with an electric strike on an existing door?

On a non-rated door, usually yes. The electric strike replaces the standard strike plate in the door frame, the frame prep (the cutout in the frame) is enlarged to fit the strike body, and low-voltage wiring is run to the location. On a fire-rated door, check first that the frame's and the strike's listings allow that preparation: enlarging the cutout in a labeled frame can fall outside its listing. The strike must be fail-secure and listed for the opening.

What is the difference between an electric strike and an electric lock?

An electric strike replaces the strike plate in the frame and works with your existing mechanical lock. An electric lock (like a maglock or electrified mortise lock) replaces the lock itself. Electric strikes are simpler to install and less expensive, but they only control entry from one side. The mechanical lock still provides free egress from the inside.

Do I need a separate power supply for each electric strike?

Not necessarily. A single power supply can run multiple strikes as long as it is rated for the combined inrush current of all strikes that could activate at the same time. Size the supply at 150% of peak calculated draw and keep wire runs within the voltage drop limits for your chosen voltage (12V or 24V DC).

How do I know if my door needs a fail-safe or fail-secure strike?

Start with the door's fire rating. On a fire-rated door the strike must be fail-secure: NFPA 80 requires fire doors to stay positively latched, and fail-safe strikes are not fire rated. The strike does not decide egress: with the usual lock and exit device functions, the door still opens from the inside. On a non-rated door, choose fail-safe if losing power should release entry from the outside, and fail-secure if the door should stay locked. When in doubt, ask the authority having jurisdiction (AHJ).

Will an electric strike work with my panic bar?

Yes, but you need a strike designed specifically for rim-mounted exit devices. Standard cylindrical lockset strikes will not fit the Pullman-type latch on a panic bar. Check the exit device manufacturer's compatibility list. Von Duprin, Sargent, and Precision all publish approved electric strike pairings for their exit devices.

What maintenance does an electric strike require?

Electric strikes are low maintenance. Test the strike monthly by triggering it from the access control system and confirming it releases and re-locks properly. Check wiring connections annually. On fire-rated doors, the electric strike must be included in the annual NFPA 80 fire door inspection. Replace any strike that shows sluggish operation or fails to fully release the latch.

Electric Strikes at US Made Supply

Browse our selection of ANSI/BHMA A156.31 rated electric strikes for commercial access control. All products include manufacturer documentation, wiring diagrams, and compatibility information.