Bonded Seals

4.5mm - 31.0mm Steel body with bonded rubber seal
Bonded Seals
Bonded Seals · Bonded Seals

Bonded seals combine a metal washer with a bonded elastomer sealing lip, sealing hydraulic and fluid connections under the fastener head or port. We supply bonded seals across a range of metric sizes.

Also known as: dowty seals, dowty washers, self-centralising seals.

Bonded Seals dimensions

Bonded Seals dimensioned technical drawing
Bonded Seals dimensions
d1d2s
4.5mm 7.0mm 1.0mm
5.7mm 10.0mm 1.0mm
6.7mm 11.0mm 1.0mm
7.1mm 11.0mm 1.0mm
8.7mm 16.0mm 1.0mm
10.7mm 18.0mm 1.5mm
12.7mm 18.0mm 1.5mm
12.7mm 20.0mm 1.5mm
14.7mm 22.0mm 1.5mm
16.7mm 24.0mm 1.5mm
18.7mm 26.0mm 1.5mm
20.7mm 28.0mm 1.5mm
22.7mm 30.0mm 2.0mm
24.7mm 32.0mm 2.0mm
26.7mm 35.0mm 2.0mm
27.2mm 36.0mm 2.0mm
28.7mm 37.0mm 2.0mm
31.0mm 39.0mm 2.0mm

Materials & strength

Metal-bonded elastomer

The metal ring controls compression and carries clamping load while the bonded lip seals the fluid path.

Frequently asked

What is a bonded seal?

A washer with an elastomer ring bonded inside a metal outer: as the fitting is tightened the rubber lip compresses against the port face and seals, while the metal ring limits compression and carries the load. Widely known by the trade name Dowty seal.

Where are bonded seals used?

Wherever a pressurised hydraulic or fluid connection passes under a bolt head, banjo bolt or adaptor - the seal replaces a plain washer at the port face.

Need Bonded Seals in a non-standard size or material?

Send us your drawing — specials quoted within 24 hours.

Send us your drawing