Bonded Washer

A bonded washer is a sealing washer with a rubber or elastomer bonded to a metal backing. It provides a seal against leaks and distributes load.

A bonded washer has a sealing washer bonded to a metal backing. It seals against a surface when a screw or bolt is tightened. It is often used with self-drilling screws to keep water out of a joint.

Bonded washers are often made with a metal backing and a rubber or elastomer seal. The metal provides strength, and the rubber gives the sealing action.

This is a general guide to checking this kind of part. It says nothing about any supplier's parts.

Ask for a certificate of conformance to confirm the materials and dimensions. On receipt, check the bond between rubber and metal. Inspect for cracks or separation in the rubber.