Purple copper rod is much more widely used than pure iron. 50% of the copper is purified into pure copper by electrolysis every year, which is used in the electrical industry. The copper here is really very pure, containing more than 99.95% copper. A very small amount of impurities, especially phosphorus, arsenic and aluminum, will greatly reduce the conductivity of copper. The oxygen content in copper (easy to mix a small amount of oxygen in copper smelting) has a great impact on the conductivity, and copper used in the electrical industry must generally be oxygen free copper.