Vis system
The standard Dnd door handles are assembled on 50mm diameter x 7mm thick roses, equipped with internal right and left hand spring system. All the internal and external components of the spring system are constructed using Nylon® PA6 (containing 30% Fibre glass). Even in conditions of high usage this material offers a excellent load capacity and is very resistant to flexible and tensile mechanical stresses, ensuring high resistance to wear and friction.
The spring system has a central spindle guide, this is to assist the fitting process and to ensure the lever handles are located in the correct position. The dnd handles on 50mm roses are supplied with wooden screws as standard (Bolt through fixing screws are available on request). To ensure correct fixing of the brass cover-rose, secure by a using the reference lip at the bottom of the spring system and push on. This item is a patented Dnd product, designed, constructed and tested within our plant in Italy.

Mechanical components
Category of use
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Grade 3: High frequency of use by the public or others with little incentive to exercise care and with a high chance of misuse.
Durability
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Grade 7: high frequency of use: 200.000 cycles.
Type of operation:
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Type B spring-loaded forniture.

UNI EN 1634-2 Ed. 2008
Fire resistance certificate
Fire resistance and smoke control tests for doors, shutter and openable window assemblies and elements of building hardware. The products can only be used for installation on doors and openable windows of similar type that had been tested according to EN 1634-2 and have been shown to have at last the same fire resistance.
Guaranteed finishes
The corrosion test in salt spray is the most critical test of those we have done on our products. 80 hours in salt spray correspond to 1 year use in normal use condition.