Bimetallic Terminals Must Ensure That The Copper And Aluminum Crimp Surfaces Are Free Of Oxide Layers.

When connecting copper terminals to aluminum wires, the presence of oxides—such as copper oxide (copper) or aluminum oxide (aluminum) at the contact surfaces of the two metals—can lead to unstable or even increased contact resistance. An oxide film is particularly prone to form on the surface of aluminum wires, and its conductivity is far lower than that of the metal itself. If this oxide film is not removed after crimping, reliable conductivity will be difficult to maintain.

Before using bimetallic lugs price list to connect copper and aluminum wires, the bare conductor surfaces of both the copper terminals and aluminum wires should be sanded or cleaned. For example, for copper terminals, the surface oxide layer can be removed with fine sandpaper or a specialized cleaner until the metal is exposed.

For aluminum wire ends, the bare wire after the insulation has been stripped should also be treated, and the aluminum oxide layer should be properly treated. Sometimes, a specialized terminal structure—such as a crimp terminal with a serrated structure designed to pierce the oxide film—can be used to improve the contact quality with the copper terminal.

Proper cable lug bimetal surface treatment not only improves contact stability but also reduces the risk of electrochemical corrosion. A potential difference exists between copper and aluminum in direct contact; once moisture or electrolytes are introduced, aluminum is highly susceptible to oxidation and corrosion.