Bonded seals
Bonded seals offer strength and flexibility in one small component for all your fixing holes
These bonded seals or ‘Dowty’ seals, are essential components in many industries. Since their invention in the 40s by the Dowty company for hydraulic suspensions of British aerial equipment, they are mainly found in the automotive, aeronautical and hydraulic industries. These small components combine the strength of metal to resist tightening and the memory of an elastomer for effective sealing. They guarantee the tightness of pressurized systems, preventing fluid or gas leaks in demanding environments. Their simple but ingenious design allows screwed connections to be effectively sealed, even under extreme conditions of pressure or temperature.
Whether you need a specific size, a particular material like nitrile, Viton, a stainless steel metal or a particular alloy, our ability to meet unusual requests makes us a useful partner for specific requirements.
Let ELASFOR review your application; we will transform your technical challenges into tailor-made solutions.
Why choose a bonded seal rather than a classic seal?
Bonded seals differ from traditional washers and gaskets in several ways. A hybrid design that combines the best of both worlds: the strength of metal and the flexibility of rubber. The result: a reliable, durable, and easy-to-install seal.
Bonded seals vs metal washers
100% metal washers (steel, copper, aluminum, etc.) are perfect for distributing loads, but they do not provide a seal. Under pressure, the fluid always finds a way through the micro-asperities.
The bonded seal solves this problem: its elastomer insert fills these imperfections and creates a seal-proof barrier from the first tightening. The metal part acts as a stop, preventing overcompression of the rubber and ensuring stable contact pressure over time.
Bonded seals vs aramid or composite gasket
A conventional flat gasket can do the job, but often at the cost of high torque and the risk of creep or deformation.
The bonded seal offers the same performance in many respects and a much lower tightening torque requirement. It adapts perfectly to the bearing surface, remains stable in the face of temperature variations, and withstands numerous disassembly cycles without loss of efficiency. The result: less maintenance, fewer leaks, and greater reliability.
Bonded seals vs standard O-rings
100% rubber seals are flexible, but at high pressure they quickly show their limits: crushing, extrusion or cutting.
Bonded seals avoids these problems thanks to its metal retaining washer. It keeps the elastomer in place, even under pressures of several hundred bars. This maintains the elasticity necessary for a good seal, while benefiting from exceptional mechanical strength.
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