Traditional arms are made of high quality steel used to mechanically support of the electrodes, and water-cooled Cu-HCP copper tubes to carry the current to the electrode.
Copper tubes are usually held by stainless steel supports welded to the body of the arm itself.
This solution was widely used in the past but electric arc furnaces and bigger ladle furnaces are now usually fitted with more reliable and efficient power conducting arms.
The major drawback is the copper tubes, which require more maintenance as they are subject to vibration (which in some cases can damage the welds or supports) and cause possible damage during the furnace loading phase.
