Brass is industrial pure copper with a melting point of 1083°C, no allotrope transformation, and a relative density of 8.9, which is five times that of magnesium. It is about 15% heavier than ordinary steel. It has a rose-red color and turns purple after forming an oxide film on the surface, hence the name "purple copper." It is copper containing a certain amount of oxygen, also known as "oxygen copper."

Brass is highly malleable. A drop of pure copper the size of a water droplet can be drawn into a thin wire over two kilometers long, or rolled into a foil larger than a bed and almost transparent. The valuable property of brass is its excellent conductivity, second only to silver among all metals. However, copper is much cheaper than silver, making it the "leading role" in the electrical industry.