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CISA 52864 70 mm Backset Function D heavy-duty escape mortise lock (152864700)

Function D heavy-duty escape mortise lock: Backset: 70 mm; Faceplate width: 22 mm; Case: Galvanized steel; Latch: Reversible nickel-plated silent construction; Faceplate ends: Rounded ends; Centre distance: 85 mm; Function: D; Bolt throws: 1; Square spindle: Split; Inside operation: Handle or escape device operates latch and bolt; Outside operation: Handle operates latch; Key operation: Bolt-only operation on both sides.

152864700 backset 70 mm measurement-reference diagram; not a product view
Drawn by this site from the explicit dimensions of the corresponding model; the diagram is not to scale and is not a drilling template.

Specifications

Backset
70 mm
Faceplate width
22 mm
Case
Galvanized steel
Latch
Reversible nickel-plated silent construction
Faceplate ends
Rounded ends
Centre distance
85 mm
Function
D
Bolt throws
1
Square spindle
Split
Inside operation
Handle or escape device operates latch and bolt
Outside operation
Handle operates latch
Key operation
Bolt-only operation on both sides

Construction and operation of this version

152864700 is an explicit ordering row in the 52864 series with backset 70 mm. With function D, after opening from inside, the bolt remains retracted when the door closes again; the outside handle remains enabled and can retract the latch. This access state differs from function B, where the outside handle remains disabled; selection should follow actual access-management needs.

How to check installation dimensions

This model's backset is 70 mm, the distance from the specified door-edge faceplate reference to the operating axis. Faceplate width, centre distance and external lock-body depth describe different directions and must not substitute for one another.

For replacement, record the old lock's full number, faceplate-end shape, inside and outside operating components and strike positions; when changing handing or linked rods, confirm interfaces according to the product instructions.

Limitations

  • Series certification and catalogue descriptions of fire or escape applications do not mean this model meets current requirements when installed in any door assembly.
  • Check accessories against the corresponding model and installation instructions; Cylinders, rods and escutcheons listed as available on request are not standard equipment.

Sources

CISA 2026 English catalogue, PDF page 352 / printed page 348

Manufacturer documents are provided in their original language.

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AboutManufacturer documents are provided in their original language.