DIN 18252 Profile Cylinder Standards: Cam Timing, Keyway Profiles & Fire-Rated Door Compatibility

Executive Engineering Overview

DIN 18252 is the authoritative German national standard governing profile cylinders for mortise locks. It establishes the physical envelope, 30° cam resting timing, keyway broaching symmetry, and temperature thresholds required for seamless interoperability with DIN 18250 / DIN 18251 fire-rated mortise lockcases.

In Central European and global industrial installations, DIN 18252 compliance guarantees that cylinders from any certified manufacturer will install smoothly into standard DIN teardrop cutouts without binding against the lockcase or door handles.

DIN 30° Cam Resting Geometry & Safety Timing

The defining mechanical characteristic of a DIN 18252 cylinder is the resting angle of the central drive cam:

1. Resting Angle: When the key is removed, the cam must lock in an asymmetric resting position angled at 30° relative to the vertical centerline (tucked inside the cylinder body envelope).
2. Operational Rationale: This 30° tucked position ensures that the cam does not protrude beyond the 10 mm cylinder waist. If the cam rested vertically (0°), it would engage the mortise lock bolt thrower, preventing emergency egress or causing lock binding during door thermal expansion.

Fire-Rated Door Integration (DIN 18250 / EN 1634-1)

On fire barriers and smoke containment doors (T30, T60, T90 ratings):

• Melting Point Threshold: Cylinder body and plug must be manufactured from materials with a melting point >= 850°C (solid brass or steel; zinc components are strictly prohibited).
• Thermal Distortion Clearance: Under 1,000°C furnace exposure, the cylinder cam must not expand or seize, ensuring emergency service personnel can still operate the mechanism.