BONDED SEALS (DOWTY SEALS)

Bonded Seals (Dowty Washers)

At Ashton Seals, we supply a comprehensive range of bonded seals (also known as Dowty washers) designed to deliver reliable sealing in high-pressure environments.

Widely used across hydraulic, pneumatic, and mechanical systems, bonded seals provide a simple yet highly effective sealing solution for threaded fasteners and fittings.

A selection of Bonded Seals in different sizes

What Are Bonded Seals?

A bonded seal consists of a metal outside ring and an inner ring of rubber elastomer that acts as a gasket to provide a sealing action. This same basic concept can also be used to produce customised shapes for specific applications in any of the combinations of rubber to metal or plastic bonding.

All size ranges and material combinations are available from Ashton Seals.

We can also supply Bonded Seal Kits in imperial and metric sizes or bespoke kits to suit customer requirements.

Animation showing the difference between self-centralising and non-self centralising bonded seals Bonded Seals are available with or without the Self Centralising lip. The lip is there to:

Eliminate Seal Offset
Eliminate Leaks
Ease of Installation
Reduce Assembly Time
Captive Assembly

For more information on specifications and compatibility, you can access our Bonded Seals PDF Brochure we also have a Literature Section with our full product range.

Key Features & Benefits

Excellent sealing performance at high and low pressures
Suitable for hydraulic and pneumatic systems
Resistant to temperature fluctuations and aggressive media
Metal ring prevents over-compression and extrusion
Reduces required bolt torque while maintaining seal integrity

Applications

Bonded seals are widely used across multiple industries, including:
Hydraulic equipment and systems
Oil & gas applications
Automotive and heavy machinery
Fluid power systems Industrial manufacturing Their versatility makes them ideal for both static and high-pressure sealing applications.

Materials & Sizes available

We offer bonded seals in a wide range of materials and sizes, including:
Metal rings:
Mild steel
Stainless steel
Brass and aluminium
Elastomers:
Nitrile (NBR)
Viton® (FKM)
EPDM
HNBR
Available in:
Metric and imperial sizes
BSP and international standards
Custom sizes to customer drawings

Why Choose Ashton Seals?

✔ Leading UK sealing supplier since 1866
✔ Extensive stock availability
✔ Strong partnerships with global manufacturers
✔ Expert technical support and advice
✔ Bespoke manufacturing capabilities

Technical Support & Enquiries

Need help selecting the right bonded seal?
📞 Call: +44 (0) 1226 273700
📧 Email: ask@ashton-group.co.uk Or contact our technical team for expert guidance.

Frequently Asked Questions

1. What is a bonded seal used for?
Bonded seals are used to create a leak-proof seal around bolts and fittings, particularly in hydraulic and high-pressure systems.
2. What is the difference between a bonded seal and an O-ring?
Bonded seals combine a metal washer with an elastomer seal, whereas O-rings are entirely elastomeric and require a groove for installation.
3. What are Dowty seals?
Dowty seals are another name for bonded seals, originally developed by the Dowty Group and now widely used across industry.
4. When should I use a self-centralising bonded seal?
Self-centralising bonded seals are ideal when precise alignment is required, helping to reduce installation errors and improve sealing performance.
5. Can bonded seals be customised?
Yes, bonded seals can be manufactured in custom sizes, materials, and configurations to meet specific application requirements.

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