Motor lock STEP 552

for door environments with high-security requirements and door automation

Motor lock STEP 552 provides the opportunity to achieve high-rated burglary protection in combination with door automation, fire safety requirements, and evacuation according to EN 179. Designed for high-frequency door environments.

The lock case is made of stainless steel and has a modern bolt placement with the hook bolt located in the center of the lock case. This powerful lock can be installed in door environments that are used frequently.

For door environments with the toughest burglary requirements

STEP 552 is one of the most secure motor locks on the market and can be installed in door environments with the most stringent burglary protection requirements. The hook bolt is extremely strong, fast, and can withstand significant stress.

The lock is suitable for security class 1, 2, 3 according to SSF 200 and is certified for the highest burglary protection, class 5, according to SSF 3522, as well as Grade 7 according to SS-EN 14846:2008. It can be included as a locking mechanism in many well-reputed security door fittings for class RC3 and RC4.

STEP 552 has an extremely strong hook bolt that is also blocked and locked in the closed position. The breaking strength is 56 kN (5,600 kg). The lock also has a panic lock function.

Evacuation and re-entry

STEP 552 also serves as an evacuation lock in SSF 3522 class 2B when used with STEP Exit emergency exit devices. It can be equipped with an angled emergency device for alarmed exits or with SplitGo device for continuous use in push position. Certified according to EN 179:2008.

During evacuation, the control unit can manage re-locking or re-entry in several ways that can be customized to the needs of the facility. Continuous re-entry, time-controlled, and/or fire alarm-controlled.

Recovery of the re-entry mode can be done with a key, a reset input, or a reset fire alarm.

For doors with fire safety requirements

Certified in fire resistance class E/EI120 according to EN 14846:2008.

Unique automatic latch bolt enables opening with door automation

STEP 552 has exactly the same fine features and technologies as STEP 550. The difference between the two motor locks is that STEP 552 has a uniqe automatic latch bolt.

The automatic latch bolt functionality

When the door opens electrically, the automatic latch bolt can fold witch enables the door to be opened with door automation. Directly after the door is opened, the automatic latch bolt extends out and anchors itself in its original position, functioning again as a classic latch bolt.

STEP 552 is therefore the obvious choise in door environments where you want increased accessibility.

Fire containment and high wear resistance

Since the automatic latch bolt looks like a classic latch bolt, it distributes the wear resistance over its entire surface. It also ensures that the fire containment is maintained, even if there is a gap between the bolt and the striking plate. This, in combination with STEPs Preload technology, allows STEP 552 to withstand high pressure and ensures a high reliability.

Control unit with many smart features

The control unit ST500C uses encrypted communication OSDP AES-128 for locking, unlocking and status indications. It can handle up to two motor locks. These can be controlled individually or synchronized for connection to access control systems, alarms and central function.

Re-entry options

With STEP 552, you have the ability to configure several different re-entry options through the control unit:

  • No re-entry
  • Fire alarm-triggered re-entry
  • Mechanical re-entry + optional fire alarm-triggered (override)
  • Timed re-entry 3-60 minutes + optional fire alarm-triggered (override)

The re-entry function can be reset via a key, reset signal, or reset fire alarm.


Read more about STEP control units


Manipulation protected barrier

The lock has a double blocking, where the hook bolts block also has a manipualtion protected barrier. The barrier’s position is monitored by an optical sensor, ensuring that it is indeed locked. The barrier is completely shielded from access, thus providing protection against tampering.

With unique FreeDrive® technology

The FreeDrive® technology enables the locks motor and gearbox to disengages every time the door unlocks mechanically. This means that the wear minimizes when using lever handle, knob, keys or emergency exit device. Locks with FreeDrive® used together with STEP Exit on doors with emergency exits can therefore be used thousands of times every day.


Functional description STEP 552
  • The hook bolt and the automatic latch bolt locks/unlocks electrically, via opening signal from access control system, code lock, push button or similar.
  • The hook bolt lock/unlocks mechanically via cylinder follower.
  • The automatic latch bolt retracts mechanically via the lever handle follower with lever handle, from the interior and exterior side.
  • The automatic latch bolt is reversible to fit both right and left hung doors.




FreeDrive® minimerar slitage vid mekanisk användning

FreeDrive® är en teknik som gör att låsets motor och växellåda helt frikopplas varje gång dörren låses upp mekaniskt. Det gör att slitaget minimeras vid användningen av vred, nyckel eller utrymningsbehör. Lås med FreeDrive® används därför med fördel tillsammans med STEP Exit i dörrar i utrymningsväg och kan användas tusentals gånger varje dag.

Manipulationsskyddad spärrteknik

En spärrfunktion spärrar hakregeln automatiskt vid utlåsning. Samtidigt känner en indikering av spärrens läge så att du kan lita på att det verkligen är låst. Spärren är helt skyddad från åtkomst och säkerställer därmed skydd mot manipulation.

Combine with STEP Exit to maximize the benefits of FreeDrive®

Combine with the STEP Exit emergency exit device to create a safer evacuation route with unparalleled user-friendliness and, furthermore, to maximize the benefits of the FreeDrive® technology.

The FreeDrive® technology disconnects the motor and gearbox, meaning that they are never affected when the exit device’s lever is used. As a result, the impact on the motor and gearbox is minimized, even if the exit device is used thousands of times each day.


Go to STEP Exit for STEP 552

Security: Grade 7 SS-EN 14846. + Klass 5 SSF-3522.
Fire approved: E/EI120
Certified according to: EN 179:2008
Factory tested: 1 700 000 cycles
Functional description
  • The hook bolt locks/unlocks electrically via opening signal from access control system, code lock, push button or similar. The automatic latch bolt locks/unlocks electrically via an open signal from the access control system, code lock, push button or similar.
  • The hook bolt lock/unlocks mechanically via cylinder follower.
  • The automatic latch bolt retracts mechanically via the cylinder follower with pressure from the interior and exterior side.
  • The automatic latch bolt is adapted for both right and left.
  • Certified in class 5 according to SSF 3522.
  • Certified in Grade 7 according to EN 14846.
  • Certified in Grade L for corrosion, temperatures and humidity, which corresponds to high requirements according to EN 14846.
  • Certified in fire technical class E/EI120 according EN 14846:2008.
  • Certified for evacuation according to EN 179:2008.
Product characteristics
  • Unlocks in less than 0.1 second.
  • Modern bolt placement.
  • Unique automatic latch bolt.
  • 56 kN (5 600 kg) breaking strength.
  • Panic lock function.
  • Lock case in stainless steel.
  • FreeDrive®
  • Manipulation-protected barrier technology.
  • Back set 50 mm.
  • Encrypted communication OSDP AES-128.
  • Guaranteed opening, even if the door is subjected to pressure of up to 80 kg.
  • Evacuation and re-entry are ensured together with STEP Exit emergency exit devices.
Status indicators for
  • Bolt locked
  • Bolt open
  • Lock alarm
  • Door open/closed
  • Exit alarm
  • Four programmable AUX outputs. Choose from the following:
    • Vital open (door open)
    • Vital closed (door closed and locked)
    • Service
    • Tamper
    • Exit alarm
    • Door alarm
    • Timer failed
    • Timer unlocked
    • Timer locked
    • Door auto (activation of door automation after unlocking)
  • The control unit can handle temperatures from -5 to +70 degrees.
  • The lock can withstand temperatures from -20 to +70 degrees.
Article number E-nr Description
ST552 5868165 STEP 552 Motor lock. Incl. ST552, connection cable with adapter ST0917H, drill protection ST1199, screw and connector set ST1192.
ST552LB 5868166 STEP 552 Motor lock set with Motor lock and control unit. Incl. ST552, STEP Control unit ST500C, connection cable with adapter ST0917H, drill protection ST1199, screw and connector set ST1192.
ST552KPL 5868167 STEP 552 complete set. Incl. ST552, STEP Control unit ST500C, STEP Lead cover ST1283, 10 m connection cable ST0916H, mechanical strike plate ST9009-15, connection cable with adapter ST0917H, drill protection ST1199, screw and connector set ST1192.
Power consumption STEP 552
  • Voltage: 10-30 V AC / DC.
  • Power consumption at rest: 70,8 mA at 24 V DC.

For dimensioning of the power supply, see details in the installation manual.

Dimensional drawing STEP 552


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