Fibre Washers

Fibre Washers

Fibre washers (compressed fibre or bonded fibre sealing washers) provide a soft, compressible sealing face at bolted joints, fittings and pipe connections — sealing against fluid and gas leakage where a metal-to-metal joint would not seal reliably. AIMS Industrial stocks fibre washers in compressed fibre and rubber-bonded grades for plumbing, hydraulics, pneumatics and general engineering sealing applications.

How Fibre Washers Work

When a bolted or screwed joint is tightened, the fibre washer compresses slightly under the load — conforming to minor surface irregularities on both faces and creating a continuous sealing contact around the bore. This is particularly effective at pipe union faces, valve body sealing faces, hydraulic port plugs and inspection covers where machining tolerances or surface finish would otherwise allow fluid seepage under working pressure. Fibre washers are a sacrificial sealing component — they are designed to be replaced each time the joint is disturbed.

Material Types

Compressed fibre (CAF — compressed asbestos fibre replacements, now made from aramid, glass or vegetable fibre) is suitable for water, oil, fuel and low-pressure steam applications up to moderate temperatures. Rubber-bonded fibre washers provide better sealing on rough faces and are used in hydraulic fittings and fuel system connections. For high-temperature and high-pressure applications, copper sealing washers or PTFE-face washers may be the more appropriate solution.

Sizing

Fibre sealing washers are sized by inside diameter (bore to match the fitting or bolt) and outside diameter (sealing face area), in metric and imperial series to suit standard pipe fittings, bolt sizes and hydraulic port plugs. For help identifying the right sealing washer for your application, contact our team. AIMS Industrial has been supporting Australian industry since 1988.