Copper rods can be mainly classified according to their production process, oxygen content, and state. Based on the correlation between production process and oxygen content, they are mainly divided into oxygen-free copper rods and low-oxygen copper rods.
Oxygen-free copper rods are mainly produced using the top-drawing method or dip-coating molding method. According to their state, they can be divided into soft state (R) and hard state (Y), where soft state (R) is the direct casting or annealed state, and hard state (Y) is the state after further machining. The main grades are TU1 (purity ≥99.99%, oxygen ≤0.001%) and TU2 (purity ≥99.95%, oxygen ≤0.002%). Compared to low-oxygen copper rods, oxygen-free copper rods have advantages in resistivity and processing performance due to their lower oxygen content and higher purity, and are especially suitable for drawing special diameter cables. Low-oxygen copper rods are mainly produced using the continuous casting and rolling method.
Its grades include T1 (copper ≥ 99.9975%), T2 (copper ≥ 99.95%), and T3 (copper ≥ 99.90%), with T2 being the mainstream product in the market. Low-oxygen copper rods have a heat-worked microstructure, with an oxygen content typically between 200-450 ppm (sometimes as high as 700 ppm). Its production process is mature and cost-effective, offering significant advantages when drawing copper wires with a diameter > 1 mm. It is widely used in conventional power cables, magnet wires, building wires, and other electrical products where cost is sensitive or specifications are large.