Aluminium Alloy Tubular Bi-metallic Terminals lugs The barrels are kept filled with grease so as to avoid oxidization of the Aluminium. These are designed to accept a variety of conductor forms especially low stranded compacted conductors. These Terminals lugs are mainly used to terminate on copper bus bars. Whenever aluminium ring terminated on to copper or copper based alloy Terminals lugs without suitable plating, results in the corrossion of the joint over a period leading to higher joint resistance.