Three U.S. Bureau of Mines test series showed statistically that there was no advantage for gas injection through the electrode tip, and that the geometry of the electrode should be smooth shaped (conical) to make a significant difference in the amount of energy consumed. Also affecting energy and electrode consumption was the furnace atmosphere composition. An inert composition of 95 pct he and 5 pct ar saved on both energy and electrode consumption when compared with an air atmosphere. Electrode tips with an axial hole but no gas injection, and in an ar atmosphere, appeared to provide a good initial arc rooting surface. This type of electrode tip promoted uniform electrode tip wear and more efficient heat transfer. The axial holed electrodes transferred energy approximately 2 and 3 pct more efficiently than either solid electrodes or axial holed electrodes with gas injection, respectively. The center hole did not adversely affect electrode consumption or energy consumption. This could indicate that the addition of an axial hole to electrodes could improve heat transfer efficiency without any adverse effects. This especially could be true in ladle metallurgy, where a smooth surface metal bath is present. Other studies have indicated that hollow electrodes also reduce refractory wear in ladle operations.