Bimetallic Washers / Transition Washers

SED stock and distribute two types of Bimetallic/Transition Washers. The TW-range manufactured by Sicame Electrical Developments Ltd, and the PBST-range manufactured by Mecatraction.

The TW-range consists of a sharply profiled copper alloy washer encapsulated in protective grease. When inserted between the mating faces of a bolted connection the sharp profile penetrates surface oxide films and the grease is extruded to form a seal against corrosion. The washers are circular in shape.

This type of Transition Washer is designed for use between aluminium and copper/tinned copper surfaces, and is available with various sizes of stud hole. They can be used with both compression and mechanical lugs, are suitable for all types of switchgear.

The PBST-range of Bimetallic/Transition Washers are available in both circular and rectangular profiles, offering a larger area of contact between the aluminium and copper/tinned copper surfaces. Unlike the TW-range, the PBST-range does not require contact grease, as they are a two-sided washer: aluminium and copper.