CW004A is an electrolytic tough pitch (ETP) copper grade known for its very high electrical conductivity. As a high-purity copper with controlled oxygen content, it is widely used in applications where excellent electrical performance is required but full oxygen-free properties are not necessary.

Typical uses include electrical conductors, wiring, busbars, switchgear components, and various power-distribution parts. CW004A’s balance of conductivity, formability, and cost-efficiency makes it one of the most commonly used copper grades in the electrical industry.