Why select Bonded Seals
Bonded seals, also known as Dowty seals or Dowty bonded washers, are engineered for high-pressure face sealing across mechanical, hydraulic and pneumatic assemblies. They combine a metal washer and elastomer ring, bonding the sealing lip to the inner diameter so the joint is both simple to install and highly repeatable.
Originally designed to replace copper washers on fittings, the metal body controls compression and prevents the elastomer from deforming under load, making bonded seals ideal wherever reliable sealing must be retained after multiple torque cycles.
Characteristics
- Performs in both high and low pressure environments.
- Wide temperature capability aligned to the elastomer selected.
- Reduced bolt torque without losing clamp load.
- Metal stop eliminates over-compression of the sealing lip.
- Suitable for static face sealing on banjo bolts, adaptors and flanges.
Material combinations
The most common washer types are mild or stainless steel, but we can also source more unusual alloys or apply coatings where corrosion resistance is critical. Elastomeric elements are bonded to suit the media they will see in service.
Bonded seals are available in the following materials:
- Mild steel, stainless steel, brass or aluminium retainers.
- Nitrile, EPDM, silicone and FKM sealing elements.
Thread ranges & styles
Eastern Seals supplies both standard and self-centering constructions so installers can choose between classic bonded washers or versions that locate themselves during assembly.
- Bolt size (imperial) ranges.
- BSP and BSPT hydraulic fittings.
- German metric and French metric series.
Self-centering seals eliminate offset and simplify installation, and can be matched with imperial, metric, German or French standards. These seals are readily available from 1/8" through 3" with extensive French and German metric stock profiles — contact us for the latest catalogue and material specification tables.
