What Are Bimetallic Terminal Blocks Made Of? Material Selection And Fitting Guide

Bimetallic terminal blocks consist of high-purity electrolytic copper (99.9%) molecularly bonded to electrical-grade aluminum (99.5%) through solid-state friction welding. This dual-metal construction prevents galvanic corrosion when connecting aluminum conductors to copper busbars. An anti-oxide compound fills the aluminum socket to stop oxidation, while a tin-plated finish protects the copper interface against environmental degradation.

How Material Composition Affects Performance

Metal selection directly influences electrical resistance and thermal expansion stability under varying loads. The aluminum barrel accepts aluminum cables to match expansion rates, preventing loose mechanical joints over time. Meanwhile, the copper palm secures conductivity at switchgear interfaces. Utilizing proper bimetallic lugs eliminates oxidation risks at contact points, preserving electrical flow across distribution networks.

Practical Selection and Installation Steps

Material Selection Rules

1. Match conductor cross-section dimensions with terminal barrel sizing.

2. Confirm barrel surface treatment compatibility with regional atmospheric humidity levels.

3. Ensure a bi metal cable lug incorporates factory-applied joint compound inside the socket.

Field Fitting Steps

1. Strip cable insulation without scoring underlying wire strands.

2. Wire-brush the bare conductor surface to remove existing aluminum oxide films.

3. Insert the conductor fully and execute hex-die crimping across bi metal lugs connectors to establish gas-tight connections.

Component Material Specifications