Motor lock STEP 551

STEP 551 is a powerful and fast motor lock for door environments with high demands on safety.

The technical advanced hook bolt is extremely strong, fast and withstands great stresses. 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.

STEP 551 is adapted for use in door environments with the absolutely toughest intrusion protection requirements. Certified in Class 5 according to SSF 3522, and in Grade 7 according to SS-EN 14846.

Manipulation protected block function

A patent-pending block function automatically block the hook bolt when locked. At the same time, an indication locates the blocks position so you can trust that it really is locked. The block function is completely protected from access and thus ensures protection from manipulation.

Control unit with many smart features

The control unit uses encrypted communication 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 essential function. The control unit handles re-entry and day locking.

For door environments with night locking

Motor lock STEP 551 is without latch bolt and fits well as a secure night lock with the motor lock placed as an extra lock. At the end of the working day, the motor lock can secure the room as a night lock connected to a so-called essential function. Depending on the selected day lock, the motor lock also fits well with door automation.

With unique FreeDrive® technology

The FreeDrive® technology disengages the motor in both locked and unlocked positions, allowing the lock to be independently used electrically and mechanically.

Se the motor lock movie


Outstanding use in emergencysituations

STEP Exit emergency device

STEP 551 in combination with STEP Exit emergency devices gives you the opportunity to create a safer evacuation exit with unmatched user-friendliness because the pressure is used in exactly the same way as in a normal passage.

FreeDrive® technology gives the products unmatched longevity

STEP 551 is equipped with FreeDrive®. The unique technology disengages the engine and gearbox, which means that they are never affected when the the evacuation device handle is used. This eliminates the wear of the engine and gearbox completely – even though the handle may be used thousands of times every day.


Fire approved: E/EI 120*
(* in combination with other lock.)
Security: Grade 7 SS-EN 14846. + Klass 5 SSF-3522.
Certified according to: EN 179:2008
Factory tested: 1 700 000 cycles
Product characteristics
  • Unlocks in less than 0.1 second.
  • Modern bolt placement.
  • 5600kg breaking strength.
  • The control unit handles day locking.
  • Durable material choises with lock case in stainless steel.
  • FreeDrive® technology.
  • Manipulation-protected barrier technology.
  • Back set 50 mm.
  • Encrypted communication AES-128.
  • Power consumption: 32 mA at rest, max 255 mA for about 20 ms.
  • Guarantees opening even if the door is subjected to pressure of up to 5 kg.
  • Connection to the motor lock is via RS-485.
  • Prepared for OSDP.
  • Evacuation and re-entry are ensured together with STEP Exit emergency exit devices adapted for motor locks. Certified according to SS-EN 179:2008.
  • 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
ST551 STEP 551 Motor lock. With modern bolt placement. 50 mm back set.
ST551 KPL STEP 551 Complete set. Incl. ST551, STEP Control unit, STEP Lead cover, 10 m halogen-free cable, mechanical strike plate, skrew and magnet set.
ST551 LB STEP 551 Lock and Control unit set. Incl. ST551, STEP Control unit, 20 cm cable and skrew set.
Power consumption STEP 551
  • Voltage: 15-30 V AC/DC.
  • Power consumption: 24 V DC: 59 mA.

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

Dimensional drawing STEP 551


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