Double Keyed Euro Cylinders vs Single Keyed: Security vs Egress Applications
Engineering Overview: Technical evaluation of double key-operated Euro profile cylinders versus single/half exit cylinders, balancing physical security and life safety egress.
Technical & Engineering Specifications
| Standard | EN 1303:2015 Class 6 |
|---|---|
| Application | Perimeter Glass Doors, Balconies, Utility Rooms |
| Clutch Options | Standard Fixed Clutch or BS Dual Emergency Clutch |
| Cylinder Types | Double Key / Single Key (Half) Euro Profile |
| Body Length Range | 30/30 mm to 60/60 mm (Double) / 10/30 mm to 10/60 mm (Half) |
Architectural Engineering Overview
Selecting between Double Keyed Cylinders (key-operated on both interior and exterior) and Single/Half Cylinders requires balancing anti-tamper security against life-safety building codes (EN 179 / EN 1125).
Key Functional Distinctions
- Double Keyed Cylinders: Prevent intruders from breaking adjacent glass lites and reaching inside to turn a thumbturn. Both sides require authorized physical keys.
- Single / Half Exit Cylinders: Installed in exit-only doors, electrical risers, and panic exit hardware where external key access is prohibited.
Emergency Override Considerations
Double cylinders in commercial facilities should specify dual-sided clutch mechanisms to permit exterior unlocking during emergencies even if an interior key is inserted.
Frequently Asked Engineering & Selection Questions
Q1: Why are double-keyed cylinders used on glass doors?
They prevent burglars from smashing glass panels and simply reaching inside to turn a thumbturn knob to open the door.