Special Products


Derby, D251, High Heat Silicone

Product Definition
Derby D251 high heat silicone is a high performance silicone improved for sealing, adhesion and repair works which need resistance to high heat. In constructions, it is an ideal filler for joints which may be exposed to high heats. It is a silicone with elastic hardness which reacts with atmospheric humidity.

It is resistant up to 250°C for exposure to continuous heat and 300°C for temporary exposures. Acetoxy system cures, it is vulcanized at room temperature. 100% silicone. Quick curing, high resistan- ce. After curing, it is resistant to mechani- cal forces. It preserves its flexibility in between -40°C and +250°C. No cracks, no volume loss. It does not become fragile. It is single component.

The places of use
It is used for sealing and adhesion in automobiles and the other vehicles, for sealing and sealant in heating systems,  for  sealing  works  in  stoves, for sealing in heating devices, pumps and motors, for sealing, adhesion and providing sealant in the other applications to be worked on stoves and high temperatures.

Shelf life
It is 12 months when it is stored in its original closed package at room temperature.

It may cause corrosion for precisi-on metals (zinc, brass, copper etc…), marble and the other natural stones. It cannot be painted. It is not suitable for some parts which are in contact with fuel, diesel and oils.It may be harmful for the respiratory system to inhale the vapour generated in the course of curing for a long time. For this reason, you should pay attention to use in places with good air conditioning. Avoid from long-term contact with uncured silicone.

Chemical Structure Silicone Polymer  
Cure Mechanism Oxime  
Density 1.17± 0.02 g/ml (ISO 1183)
Shore A Hardness 25-30  (28 days later)       (ASTM C661)
Max. Tensile 2N/mm² (ASTM D412)
Shell Formation 10-15 min. (23°C and 50% R.H) (ASTM C679)
Curing Speed 2 mm/day (23°C and 50% R.H)  
Tensile Strength 0,3N/mm² (23°C and 50% R.H) (ISO 8339)
Breaking Strain ≥ 400%  (ISO 8339)
Elastic Rebound ≥ 80% (ISO 7389)
Hanging 0 mm (ISO 7390)
Application Temperature +5°C - +40°C  
Temperature Resistance 300°C  

Color: Red

Product Name Amount per Package Package Weight/Kg Package Dimensions
D251 High Heat Silicone 30 Adet 10.50 Kg 300x260x250 mm