Korean push-pull digital lock base (mortise)

The design language that dominated Asian smart locks for a decade: a tall push-pull handle set replacing an entire mortise lock set. It is a full-replacement architecture, so the retrofit problem is not adapters — it is the lock case matrix.

⚠ needs review · Where you will meet this lock: South Korea, Japan (imported sets), Southeast Asia (imported sets)

Also called: Push-pull lock · Digital door lock · Korean mortise

Anatomy

  • Tall push-pull handle units inside and outside
  • Mortise case with latch and one or two deadbolts
  • Battery compartment inside the inner unit
  • Often a separate remote or keypad

Parameters to measure

Measure in this order: Backset (Dornmaß) → Centre distance, spindle-to-cylinder (Entfernung / PZ) → Faceplate width × length → Fixing hole pattern / pitch → Door thickness

ParameterTypical valuesTolerance that still fitsHow to measure
Backset (Dornmaß)60 mm and 70 mm are the two that matterMatch exactlyDoor edge to the case centre line.
Centre distance, spindle-to-cylinder (Entfernung / PZ)85 mm common; 72 and 92 mm occurNoneSpindle centre to cylinder centre.
Faceplate width × lengthCase faceplate 24 mm wide, 240–300 mm longMeasure the strip on the door edge.
Fixing hole pattern / pitchHandle screw pitch 38–70 mm depending on setScrew hole to screw hole on the handle.
Door thickness38–50 mmAt the lock.

Retrofit architectures that work

  • Full lock replacement on the same footprint — The old lock case is removed and a smart lock with the same footprint takes its place. This is the dominant approach in East and Southeast Asia, where push-pull digital locks replace mortise sets on HDB, condo and apartment doors.
  • Motor replacing the interior handle — The interior lever or knob is replaced by a motor unit that drives the 8 mm spindle directly. The outside keeps the original key cylinder and handle. This is the cleanest fit for mortise locks where the bolt is thrown by the key and the handle only retracts the latch.

Because the handle is replaced wholesale, the interface that needs engineering is the lock case matrix and the strike alignment, not a clamp. Publish the exact envelope you replace and ship a cardboard template.

Related standards

EN 12209

Reference devices

Recorded as engineering examples, not endorsements.

Questions

Why are Asian smart locks rarely 'retrofit'?

Because the market standardised on replacing the whole lock set at installation time, so nobody needed a clamp-over adapter. Retrofit clamps are a European answer to a European lock.

What fails first on these sets?

The motor gearbox and the battery contacts, followed by the keypad membrane in humid climates.

Sources

Engineer feedback